media: imx219: Set horizontal blanking on mode change

media: imx219: Set horizontal blanking on mode change

The driver UAPI is mode-based, allowing the user to choose a mode from a
small list based on the output size. The vertical blanking is set based on
the mode, do the same for horizontal blanking so the frame rate obtained
is constant.

Additionally, it's best to use a known-good horizontal blanking value as
choosing the value freely may affect image quality. While the minimum
value may not be the best value for horizontal blanking, at least it is
constant rather than a minimum value of a different configuration.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>