[SRU][F:linux-bluefield][PATCH v1 0/1] UBUNTU: SAUCE: platform/mellanox: Add ctrl message and MAC configuration

[Liming Sun]

BugLink: https://bugs.launchpad.net/bugs/1927253

SRU Justification:

[Impact]

* This is an enhancement to support ctrl message and BlueField side rshim
  MAC address configuration from the rshim driver.

[Fix]

* Additional new code for the enhancement. It doesn't have fix for existing code.
[Test Case]

* Set DISPLAY_LEVEL to 1 in /dev/rshim0/misc and do 'cat /dev/rshim0/misc'
  from external rshim driver. The rshim MAC address will show up.
* echo "PEER_MAC xx:xx:xx:xx:xx:xx" > /dev/rshim0/misc to modify
  the MAC address. The change will take effect in next boot.

[Regression Potential]

* This version of the driver was tested by QA/verification for a while so no
  known regression at the moment.