wifi: iwlwifi: disable RX STBC when a device doesn't support it

Some devices, like step A0 of GL FM device doesn't support RX STBC
for VHT/HE. Add a workaround to remove it from capabilities in
this case.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230524203151.65c3e09813e5.Iadfd8cdb0ea5a8088ae3daa555c780c423951894@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>