media: dt-bindings: sony,imx290: Update usage example

Since commit 98e0500e ("media: i2c: imx290: Add configurable link
frequency and pixel rate") the driver expects two specific
link-frequency settings 2-lane (445500000, 297000000) and 4-lane
(222750000, 148500000) operation. The driver fails to probe without
these exact settings.

Update the example in the bindings to match this to make it easier for
users to incorporate this sensor in their device tree descriptions
without having to read the driver sources when the driver fails to
probe.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>