m7: Fix Bluetooth sleep bugs

 * Switch to HTC's ioctl interface
 * Set polarity to low
 * Enable two stopbits for serial device

Change-Id: I69f4d60c8cb57437d455ce8fd7651f422d048a30
Merge "m7: Fix Bluetooth sleep bugs" into cm-10.1
Merge branch 'cm-10.1' into martincz