m7-common: add BTLE permission file

Change-Id: I4963ef3b3f303ed2f7205117ee20162043972511
m7-common: set /proc/cmdline permissions

Change-Id: I2c7e3ca60af783c92f7ab5c591ec77816f58b16b
m7: Enable I2SPCM slave mode for SCO

 * New mode in Bluedroid to configure firmware
 * Add ACDBID for proxy device which previously could have caused
   calibration issues.
 * Fixes Bluetooth call audio!

Change-Id: I0db5931c1ebac36ede8f4bd22e20c52673912902