recovery: Add support for split display

Configure LEFT and RIGHT mixer separately
to drive high resolution display.

Change-Id: I6923f0145a19fac725e1265a463d64cd0e1db603
safestrap/splashmenu: recovery: Add support for split display

Configure LEFT and RIGHT mixer separately
to drive high resolution display.

Change-Id: I1ea20b73b0e60cf9b9229be58de5dc1e12d65f2a