[SRU][F:linux-bluefield][PATCH v1 0/3] UBUNTU: SAUCE: pwr-mlxbf: Several bug fixes for focal

[Asmaa Mnebhi]

BugLink: https://bugs.launchpad.net/bugs/2041996

SRU Justification:

[Impact]

There is are several changes that needs to be made to pwr-mlxbf in focal:
* There is a race condition between gpio-mlxbf2.c driver being loaded and pwr-mlxbf.c being loaded
* When the module is removed, there is a panic due to NULL pointer access
* soft reset needs to be replaced by graceful reboot

[Fix]

* Fix race condition between gpio-mlxbf2.c driver being loaded and pwr-mlxbf.c being loaded
* Fix panic due to access to NULL pointer when driver is removed via rmmod
* support graceful reboot instead of soft reset

[Test Case]

* all test cases are for BF2:
* trigger the gpio toggling from the BMC: ipmitool raw 0x32 0xA1 0x02
  This should trigger a graceful reboot of the DPU.
* rmmod/modprobe
* reboot test and make sure the driver is always loaded

[Regression Potential]

* Run the 100 reboot test and make sure that the driver is loaded with no issues. That the gpio graceful reboot works.