tf700t: remove dual band support

Device doesn't seem to support 5ghz, I've research and looked and can't find
much information, removing for now until can be proven otherwise.

This coicides with: http://review.cyanogenmod.org/32326

Change-Id: Ibf4af0de265f17b57fa8bd542f38b2cc6de72bd2
Merge "tf700t: remove dual band support" into cm-10.1