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.
10 jobs for sce_add_couple_specific_props_zyng_upscale_plus in 24 minutes and 57 seconds (queued for 3 minutes and 21 seconds)
Status Name Job ID Coverage
  Preparation
passed gst indent #1309021

00:00:17

passed manifest #1309020

00:00:24

 
  Build
passed build clang fedora x86_64 #1309026

00:09:12

passed build fedora x86_64 #1309022

00:06:48

passed build gst-omx zynq fedora x86_64 #1309027

00:06:11

passed build nodebug fedora x86_64 #1309023

00:06:17

passed build static fedora x86_64 #1309157

00:10:13

passed build static nodebug fedora x86_64 #1309025

00:05:46

failed build static fedora x86_64 #1309024

00:07:07

 
  Integrate
passed documentation #1309028

00:07:23