Use highp float precision only in YUY2 color convert shaders.

- Port of e15c8166d4fcfd65c7030d53da57bd30feae7606 from
imx-gst-plugins-bad to imx-gst-plugins-base

Change-Id: I065afc9a93bbe646626566bae8f55d3191c3dfa3
1 file changed