media: ov7740: remove redundant V4L2_CTRL_FLAG_VOLATILE set

If the v4l2 controls are set up for autofoo/foo-type handling by calling
v4l2_ctrl_auto_cluster() with the last set_volatile argument setting true,
each non-auto control doesn't need to be flagged V4L2_CTRL_FLAG_VOLATILE.

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>