intel/mi: only resolve to a temp register if source isn't in memory

intel/mi: only resolve to a temp register if source isn't in memory

aka. fix a s/||/&&/ typo

Fixes: 74063ee61aadd1371a9b ("intel/mi: Add a new gen_mi_store_if() helper.")
Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>