media: ov7740: avoid invalid framesize setting

If the requested framesize by VIDIOC_SUBDEV_S_FMT is larger than supported
framesizes, it causes an out of bounds array access and the resulting
framesize is unexpected.

Avoid out of bounds array access and select the default framesize.

Cc: Wenyou Yang <wenyou.yang@microchip.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>