Merge branch 'mlxsw-couple-of-fixes'

Ido Schimmel says:

====================
mlxsw: Couple of fixes

Patch #1 fixes firmware flashing when CONFIG_MLXSW_CORE=y and
CONFIG_MLXFW=m.

Patch #2 prevents EMAD transactions from needlessly failing when the
system is under heavy load by using exponential backoff.

Please consider patch #2 for stable.
====================

Link: https://lore.kernel.org/r/20201117173352.288491-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>