msm: audio: change uapi include header files directory

Change the directory structure of uapi headers. The existing
directory structure overwrites kernel headers in /usr/include/sound
and /usr/include/linux. Hence move audio uapi headers to
/usr/include/audio folder.

Change-Id: I14ef211a65605e798174087a3f322c64768fbfc7
Signed-off-by: Vignesh Kulothungan <vigneshk@codeaurora.org>