media: i2c: imx290: Rename, extend and expand usage of imx290_pixfmt

The imx290_pixfmt structure contains information about formats,
currently limited to the bpp value. Extend it with the register settings
for each format, and rename it to imx290_format_info to make its purpose
clearer. Add a function named imx290_format_info() to look up format
info for a media bus code, and use it through the code. This allows
dropping the imx290 bpp field as the value is now looked up dynamically.

The error handling in imx290_setup_format() can also be dropped, as the
format is guaranteed by imx290_set_fmt() to be valid.

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>