Why I did it
XGS saibcm-modules 8.4 is needed. #14471
Work item tracking
Microsoft ADO (number only): 24917414
How I did it
Copy files from xgs SDK 8.4 repo and modify makefiles to build the image.
Upgrade version to 8.4.0.2 in saibcm-modules.mk.
How to verify it
Build a private image and run full qualification with it: https://elastictest.org/scheduler/testplan/650419cb71f60aa92c456a2b
Update the build rules in saibcm-modules to use the 5.10 kernel instead
of searching for the 4.19 kernel. In addition, some code changes were
done to get it to compile. The main categories of such changes are as
follows:
* For /proc files, `struct file_operations` has been replaced with
`struct proc_ops`.
* Y2038 changes to use the new APIs, since `do_gettimeofday()` is no
longer available.
* Minor changes in how external kernel module symbols are read by
modpost.
Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>
