Emit MIPI DSI Picture Parameter Set command

[MarijnS95]

Draft. This is not something I think we should actually send, since the PPS send command is already emitted if qcom,compression-mode = <DSC>;. However, if the PPS is present in device DTSI, I do want to make the user aware that it exists and give them a way to compare it with whatever the automated mipi_dsi_picture_parameter_set() sends.

Note that this PPS is built up partially by the panel driver, and then further filled in by drm/msm drivers and DRM DSC helpers. Hence differences might sometimes be key in debugging a DSC setup.

For now the PPS could be emitted to the kernel log with the following snippet, but before going ahead and emitting a print for both, does anyone know of a proper way to diff or compare and print the result instead?

print_hex_dump(KERN_INFO, "DSC:", DUMP_PREFIX_NONE, 16,
               1, (void *)&pps, sizeof(pps), false);