msm: usbaudio: Add support for USB headset detection

 - During bootup, create a file system storing the
   information about usb device state and name, and
   broadcast the message to userspace whenever the
   device is plugged or unplugged.

 - Register the device at USB sound card initialization
   for creating file system and toggle the state in that
   filesystem when USB is plugged/unplugged. This will
   also send a message to user space informing it about
   state change.

Change-Id: Icd78273bb765a26bbc70725afebe8955de8f7315
Signed-off-by: Harmandeep Singh <hsingh@codeaurora.org>
msm: usbaudio: Fix memory allocation for USB audio module init

Fix memory allocation issue in snd_usb_audio_init()
use sizeof(struct) insead of sizeof(pointer)

Change-Id: I270bbd7111e97dd4e0e92378f61d5025e16f5fca
Signed-off-by: Alex Fradkin <afradkin@codeaurora.org>
mm: optimize Kernel Samepage Merging(KSM)
mm: Adjust dirty writeback for IO boost