video: driver: Add handling for session priority

Following changes are added with this:
1. Handle and adjust session priority.
2. Session addmission based on priority.
3. Power (clock and bus) scaling based on priority.
4. Handle s_parm influence on priority.

Change-Id: I12dec5fb03d733f07b0b0a24b4d74d1ccd4bf791
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>

driver/vidc/inc/msm_vidc_inst.h

@@ -136,6 +136,7 @@ struct msm_vidc_inst {
 	struct debug_buf_count             debug_count;
 	struct msm_vidc_inst_capability   *capabilities;
 	struct completion                  completions[MAX_SIGNAL];
+	enum priority_level                priority_level;
 	bool                               active;
 	u64                                last_qbuf_time_ns;
 	bool                               vb2q_init;