[media] atmel-isi: correct yuv swap according to different sensor outputs

we need to configure the YCC_SWAP bits in ISI_CFG2 according to current
sensor output and Atmel ISI output format.

Current there are two cases Atmel ISI supported:
  1. Atmel ISI outputs YUYV format.
     This case we need to setup YCC_SWAP according to sensor output
     format.
  2. Atmel ISI output a pass-through formats, which means no swap.
     Just setup YCC_SWAP as default with no swap.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>