media: i2c: imx415: Link frequencies are not exclusive to num lanes

The link frequencies are equally valid in 2 or 4 lane modes, but
they change the hmax_min value for the mode as the MIPI block
has to have sufficient time to send the pixel data for each line.

Remove the association with number of lanes, and add hmax_min
configuration for both lane options.

Reviewed-by: Michael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: Gerald Loacker <gerald.loacker@wolfvision.net>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>