usbaudio: Merge with upstream

Change-Id: I4c06b1ea790bf2a632974c3f2f84a20aa08159f7
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>