m7-common: fstab: Add misc partition

The misc partition is used for certain recovery actions. The bootloader
message is at offset location 2048 (0x800).

Change-Id: I8c4a036026b33b9a1b895d83fd3356a83e9ae4e8
m7-common: move CDMA Telephony overlays to devices

These overlay settings are applicable to m7spr and m7vzw only, and
should be applied to more spns than 310120/311480. Move them out of
common and into the correct overlay structure for each device.

Change-Id: Id9881ca2062b6b8cdf32b19a05abd66929bd492a