wifi: iwlwifi: mvm: add set_hw_timestamp to mld ops

In mld ops, set_hw_timestamp was not set. Fix it.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230328104949.7b24a582b763.Ieb3139d41f1a01b2b566adecd32450da1bcdd5fa@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>