iwlwifi: mvm: move existing UMAC commands to group 1

Existing UMAC commands already use the long header, but are sent
with group 0 and the long header inserted manually. Move them to
the group 1 to take advantage of the header building in the low-
level transport.

Existing firmware ignores the group_id field (it's reserved) and
the first firmware that really supports long command headers can
parse all commands in both group 0 (with short header) and group
1 (with long header.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>