iwlwifi: mvm: make sure state isn't in d0i3 when collecting fw dbg

This makes sure that we're not trying to read/write any of
the FW debug data collected during d0i3.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Reviewed-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>