wifi: iwlwifi: mvm: don't set trigger frame padding in AP mode

This field is reserved in AP mode, don't set any bits in it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240129211905.f5eeb717212e.I60fa4843a8634922281580b925db2c2699e3a7bc@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>