MLK-20718-5: drm/imx: nwl_dsi-imx: Correct clk usage

For QM and QXP, the PHY_REF clock was default ON on SCFW so it was not
handled by driver. Since now this clock is OFF in SCFW, it can be
correctly handled by kernel driver.
Now, the PHY_REF clock rate is set by the nwl-dsi bridge driver,
depending on the display mode used.
In this driver, the PIXEL and BYPASS clocks rates were set to the same
rate as the PHY_REF, but their rates need to be set to current display
mode clock.
Also, the order of the clocks matters, so make sure the BYPASS is
enabled before the PIXEL clock.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
Reviewed-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>