iwlwifi: support multiple d0i3 modes

Allow configuring additional d0i3 mode, in which the
fw will be configured to enter d0i3 only on suspend
(while keeping the wake_lock accounting as usual)

The d0i3 mode to use will be determined by the
underlying trans layer.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>