v4l: vsp1: sru: Make the intensity controllable during streaming

v4l: vsp1: sru: Make the intensity controllable during streaming

The control value is currently stored in the SRU structure by the
control set handler and written to the hardware at stream on time,
making control set during streaming ineffective. Fix it by writing to
the registers from within the control set handler.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
(cherry picked from commit 58f896d859ce555dd3684f439f8a65bfda437533)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>