iwlwifi: Fix Makefile build order for built-in driver

When the driver is built into the kernel instead of a module
when the system boots it results in a panic. The order things are built in
results in their initialization order when built into the kernel. Wifi
has to be initialized before mvm or dvm.

Reviewed-by: Donald H Fry <donald.h.fry@intel.com>
Tested-by: Donald H Fry <donald.h.fry@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Brandon Misemer <brandon.misemer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>