m7-common: Move post-boot functionality into init

Change-Id: Ic089092b20708f0004076f7c86a92b37baaa296f
Fix USB tether

Change-Id: I10b19d4fb86fe477655af369726bc26ba301c0f4
m7-common: commonize some BoardConfig defines

Change-Id: I1641f8766d66d20905d29f6cd1e1a694916c83b1
m7-common: Re-enable performance profiles

Change-Id: I9ec62f112c768a0341f47092f0aa6f6a10367118