drm/imx: Add i.MX8qxp Display Controller pixel engine

i.MX8qxp Display Controller pixel engine consists of all processing
units that operate in the AXI bus clock domain.  Add drivers for
ConstFrame, ExtDst, FetchLayer, FetchWarp and LayerBlend units, as
well as a pixel engine driver, so that two displays with primary
planes can be supported.  The pixel engine driver and those unit
drivers are components to be aggregated by a master registered in
the upcoming DRM driver.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250414035028.1561475-11-victor.liu@nxp.com