Add support for the new SC8280XP binding.

Note that the binding does not try to describe every register subregion
and instead the driver holds the corresponding offsets.

Also note that (possibly) unlike on earlier platforms, the TX registers
are used by both the USB and DP implementation.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221121085058.31213-14-johan+linaro@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>