dv: enable drop frame for dv [1/1]

dv: enable drop frame for dv [1/1]

PD#SWPL-13115

Problem:
Apk drop lots of frames before render
the first frame, in this case, omx_run
is false and no frames will render.
Decoder doesn't have free output buffer.

Solution:
Drop dv frames in video sync before render
the first frame if app want to drop.

Verify:
Verified on U212

Change-Id: I463619f658d7f78ad8d513e17ca78482e17b3a4e
Signed-off-by: yao liu <yao.liu@amlogic.com>