media: xilinx: fix typo in formats table

In formats table the entry for CFA pattern "rggb" has GRBG fourcc.
This patch fixes it.

Signed-off-by: Mirco Di Salvo <mirco.disalvo@iit.it>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>