omxvideoenc: Add look-ahead property to ZYNQ_USCALE_PLUS encoder

This patch adds look-ahead property to encoder

The value indicates look ahead size in frames,
the number of frames processed ahead of second pass encoding.
Dual pass encoding is disabled if look-ahead
value is less than 2.
Status Job ID Name Coverage
  Preparation
passed #622749
gst indent

00:00:50

passed #622748
manifest

00:00:37

 
  Build
passed #622754
build clang fedora x86_64

00:07:13

passed #622750
build fedora x86_64

00:02:58

passed #622751
build nodebug fedora x86_64

00:03:35

passed #622752
build static fedora x86_64

00:10:20

passed #622753
build static nodebug fedora x86_64

00:03:28

 
  Integrate
passed #622755
documentation

00:04:39