media: i2c: imx290: Support 60fps in 2 lane operation

Commit "97589ad6 media: i2c: imx290: Add support for 2 data lanes"
added support for running in two lane mode (instead of 4), but
without changing the link frequency that resulted in a max of 30fps.

Commit "98e0500e

 media: i2c: imx290: Add configurable link frequency
and pixel rate" then doubled the link frequency when in 2 lane mode,
but didn't undo the correction for running at only 30fps, just extending
horizontal blanking instead.
It also didn't update the CSI timing registers in accordance with the
datasheet.

Remove the 30fps limit on 2 lane by correcting the register config
in accordance with the datasheet for 60fps operation over 2 lanes.
Frame rate control (via V4L2_CID_VBLANK or HBLANK) can still reduce
the frame rate on 2 lanes back to 30fps.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>