avtimer: Update avtimer driver to parse driver tree data

LPASS exposes registers from which timestamp can be
read by clients for audio & video synchronization.
Change adds to retrieve the register address of AV
timer in LPASS passing from driver tree data.

Change-Id: Id7cf3455e22ddc27f5350a7a37c3b40d44eb0873
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

avtimer: Update avtimer driver to support Qdsp6v2

AVtimer in Qdsp6 provides the timer ticks for synchronization
of audio and video streams for capture and playback use cases.
Qdsp6 AVtimer interface has been updated for v2 version.
Update avtimer driver to support Qdsp6v2.

Change-Id: Ia68b04421edf13a96685654761bb71b866a5327b
Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>

defconfig: 8974: Enable AV timer

Change enables AV timer driver which provides audio
and video synchronization clock support

Change-Id: I318de660e6f52d0c62bafc5cb2c9907fe007c997
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

ARM: dt: msm8974: Add AV timer specific data

LPASS exposes registers from which timestamp can be
read by clients for audio & video synchronization.
Change adds the register address of AV timer in LPASS.

Change-Id: Idee2aeb3cb73fcbca37976629c798abeae544774
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

avtimer: fix uninitialized variable compilation warning

Fix the following compilation warning in the avtimer driver:

kernel/drivers/platform/msm/avtimer.c:
	In function 'dev_avtimer_probe':
kernel/drivers/platform/msm/avtimer.c:316:
	warning: 'result' may be used uninitialized in this function
error, forbidden warning: avtimer.c:316
make[5]: *** [drivers/platform/msm/avtimer.o] Error 1