avtimer: kernel driver to expose avtimer to userspace

This driver expose the API to get LPASS subsystem
out of power collapsed state and exposes ioctl control to
read avtimer tick.

Change-Id: I4b50fbfca5741449a8e5f0d0514f5ca7bccec04d
Signed-off-by: Srikanth Uyyala <suyyala@codeaurora.org>