wl12xx: Stop messing with modprobe

* Logic copied from compat_wl18xx
* Without this the makefile tries to load the target modules on the host computer

Change-Id: If5cb31dfd5404c9d04da2e7c1f21a0b4674af4ab
wl12xx: Don't build wl1251 if the kernel doesn't require it

Change-Id: Ice85ec9532b21a993410c9743b9d1f5409931fe3