FM Radio support

This is a combination of 7 commits:

FM Radio support (part 1)
si4708: configure de-emphasis according to selected band
FM radio support (part 2)
Fix FM audio routing
Build libfmradio by default
si4708: add RDS support
si4708: use mute IOCTL

Change-Id: I9e1c04b4262ad525a2c3adccf1aaead684e528fd

Conflicts:
	BoardConfig.mk
	device.mk
	libaudio/Android.mk
	libaudio/AudioHardware.cpp
	libaudio/AudioHardware.h
	libaudio/AudioPolicyManager.cpp
	prebuilt/root/ueventd.blade.rc
fix