Add Pac device overlays for m7spr

This fixes the network mode selection screen that has been an issue for us
for ages.
CM isn't merging this into their device tree yet, but we should do it here
to fix our ROM and if they merge it later I will track theirs and remove
the redundancy (that won't even cause any errors) once they merge.

Change-Id: I0a9ee416776d66b8b7d21d0744de3a131011fcfc
Merge "Add Pac device overlays for m7spr" into pac-4.4