Removing the unneeded ExtraSymbols.symvers and cleaning up the FE makefile so it builds on debian 11

Adding volatile for memory mapped IO, adding function for kernel space timespec retrieval and adding test for the gpstime module

Cleaning up findSharedMemory usage, fixing error checks on the returned pointer, consolidating code for findSharedMemory() and findSharedMemorySize() so we don't have duplicate, removing unused sprintf in both functions

 * typeo in one of the commits left it as the invalid 'lingo_ioremap.h' instead of 'ioremap_selection.h'

 * ligo_iomap.h becomes iomap_selection.h to denote what it actually does.
 * LIGO_IOREMAP becomes simply IOREMAP to note that it isn't LIGO specific.

 * This allows the code to call the appropriate version if ioremap/ioremap_nocache depending on the kernel version.

Adding funtions with more general real-time/isolation language because this functionality extends to more general core isolation usecases.

 * rename from ligo_rt_* to rts_cpu_isolator_*

The ligo_rt module has the functionality of the real time patch, without the
requirement to rebuild the kernel.

 * Use the proper version of ioremap for each kernel version.
 * Use a 64bit time call in newer kernels.
 * Only use unlocked ioctls as the interface in the mbuf/gpstime code.

 * Fix the checks in mbuf_probe gap_check to catch this case
 * Add a filter to cps_recv
 * Add an integration test
 * extend fe_simulation to simulate a timing glitch that sets the wrong nano-seconds value

synchronization frequency output from -b option made to pull from correct register.

gpstime: lptc_info script now handles all "on board" registers including temperature, voltages and currents.

internal power supply registers /sysfs output changed to look like a comma separated array, same as the external supply.

Corresponding packaging changes are needed.

lptc_info.py prints useful diagnostics information about the first LIGO PCIe Timing Card that it finds attached to the PCIe bus.
It decodes various registers produced by the card and expressed in /sys/kernel/gpstime/lptc, including slot-specific registers.

gpstime module must be installed to use.  If an LPTC is not attached, then gpstime will not create the /sys/kernel/gpstime/lptc directory nor its contents.

LPTC driver and gpstime: Many more diagnostics register functions added for the LPTC driver.  These values are also brought out into the /sys file system in /sus/kernel/gpstime/lptc when gpstime is running.

Some functions added to lptc driver to expose diagnostics registers.

lptc specific diagnostics and slot-specific registers brought out in /sys/kernel/gpstime/lptc

some functions that belong to ligoPcieTiming_core.c were moved there from ligoPcieTiming.c

This is to allow the gpstime drive to access the core (init/read time) funcitons without needing to pull in all the rest of the logic to manage other boards.
This removes some ifdefs around functions that would otherwise cause gpstime not to compile while building with the LIGO card.

Added LIGO PCIe timing card to gpstime.  Some changes made to the ligo timing driver to eliminate floating point operations.

Fix a formating error

Fix a formating error and provide an example of reading/writing data or integrating with numpy.

awgtpman, mbuf: awg and testpoints now working through new mbufs for both iop and user model.  2k models need to be tested.

mbuf_probe, awgtpman: some fixes to mbuf_probe.  awgtpman now does not care about fast vs. slow models.

 * Creates a python package 'ligo_shmem' with a single class exported 'shmem'.
 * Requires pybind11 to build.

This exposes mbufs/posix shmem as a python object.

 * implements the buffer protocol, so it can be used with numpy arrays
 * provides access via slicing
 * Adds pybind11 as a build requirement.

 * Also removed a check that shouldn't be needed with the new default.

 * The buffers must be the same types (rmipcstr, daq_multi_cycle) and size.

 * Updated cps_xmit/recv, cds_pub_sub, local_dc to work with posix shmem or mbuf
 * Add tests that use posix shmem for daqd, cps_recv/xmit, cds_pub_sub, local_dc

This also allows the use of posix shared memory instead of mbuf if the proper name is passed in.