media: i2c: imx290: Compute pixel rate and blanking in one place

Upstream commit 693b5cb5

The hblank, vblank, pixel rate and link frequency values and limits are
currently computed when creating controls, in imx290_ctrl_init(), and
updated in imx290_ctrl_update(). This duplicates the logic in different
places. Simplify the code by setting the control values and limits to
hardcoded values when creating the controls, and call
imx290_ctrl_update() to then update them.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>