[BUGFIX] wifi: iwlwifi: mvm: forbid power save if the device was powered off

If the device was power gated during an S3 cycle, we will face issues
that we don't fully understand. Those issues are related to power save
in the firmware and they cause timeouts on the commands sent by the
driver to the firmware.
Analysis showed that the firmware does send the command response and the
driver can see the response in the Rx ring, but the driver doesn't get
the interrupt. Accessing the CSR registers is enough to get the
interrupt.

It is unclear why the driver doesn't get the interrupt.
This situation is quite rare because it requires a few conditions:
1) the network manager needs to not shut down the device upon suspend
2) the platform power gates the device during S3

Because of that, just disable power save when this situation is
detected.

type=bugfix
ticket=jira:WIFI-895165
fixes=unknown

Change-Id: I57f5a246848d0479a63b3eccad6f5a71be7e6949
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-on: https://gerritwcs.ir.intel.com/c/iwlwifi-stack-dev/+/297601
tested: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
automatic-review: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Tested-by: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
x-iwlwifi-stack-dev: c9d10d23cc4266ee6cd82b23de2abe353a1e8f6d