Fix wrong permission of /data/system.

This caused boot failure.
Enable audio.

libaudioalsa/alsa.c came from https://github.com/Victor-android/android_device_huawei_u8800pro/blob/master/libaudio/alsa.c
Modifications of alsa.c.
 * Add 3 more controls. Reset, DualMic Switch, Device_Mute
 * msm_set_volume(int, int) -> msm_set_volume(int, float)
 * msm_en_device(int, int) -> msm_en_device(int, short)
 * All methods return error codes on failure case
 * Lots of style fixes