msm8960: kill this samsung service mode with fire

Change-Id: I8b6a05580ad034c38f2884866d62a57e4a999c4b
msm8960-common: fix up tethering

Without this tethering fails on T-Mobile and Sprint. Not needed until
http://review.cyanogenmod.org/#/c/55035/5 was merged.

Change-Id: I07e3b86bffa8d4ffa45a4908380d6c7e0f5bfe06
msm8960-common: unified bringup

Change-Id: I1d99433b2681f33a2d9b0e006f1a3333ebd8b100