Merge branch 'net-ipa-enable-register-retention'

Alex Elder says:

====================
net: ipa: enable register retention

With runtime power management in place, we sometimes need to issue
a command to enable retention of IPA register values before power
collapse.  This requires a new Device Tree property, whose presence
will also be used to signal that the command is required.
====================

Link: https://lore.kernel.org/r/20220201150205.468403-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>