msm8974: Add ultra-low-latency audio instance

 * Replace deprecated LPA output with new ULL feature.

Change-Id: I81bcf998ccf0740509a40d9c166dad07d7337bf3
msm: mdss: Updates:

* msm: mdss: Add missing BL lock around BL-related info
The bl_updated variable requires the BL lock. Otherwise, it can be
corrupted and cause backlight issues.

Signed-off-by: Benet Clark <benetc@codeaurora.org>

* Updated panel driver from stock I9506 kernel source.
* Fixed MDSS_EVENT_CONT_SPLASH_FINISH handle. Fixes backlight issue.

Change-Id: I489f5faebfb3ced8c3a857553b7c333245596912