video: driver: Add support dynamic low latency for decoder

Latency property is set to firmware during streamon output port,
if set as part of initial configuration by client.
During runtime, the property is set as and when configured by
client.

1. Make the latency property dynamic for decoder.
2. For encoder, the same gets set to firmware with regular
   v4l2 set properties.
3. For decoder, set the property explicitly during streamon
   output port.

Change-Id: I35990614b95e57f113ddacfc2272cad6ae0dde82
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>

driver/vidc/inc/msm_vidc_control.h

@@ -86,6 +86,8 @@ int msm_vidc_set_blur_type(void *instance,
 	enum msm_vidc_inst_capability_type cap_id);
 int msm_vidc_set_blur_resolution(void *instance,
 	enum msm_vidc_inst_capability_type cap_id);
+int msm_vidc_set_stage(void *instance,
+	enum msm_vidc_inst_capability_type cap_id);
 int msm_vidc_set_s32(void *instance,
 	enum msm_vidc_inst_capability_type cap_id);
 int msm_vidc_set_q16(void *instance,