m4: Move radio properties back to system.prop

Build system does not handle properties containing whitespace
properly, so instead of making collapse-pairs smarter and potentially
breaking stuff, be lazy and shove the lot back into a separate file.

Change-Id: Ie04a615d79f277370f5cbea3e69d6ddb1a0597d0
Merge remote-tracking branch 'cm/cm-12.0' into HEAD