drm/dsi: clean up DSI data type definitions

Rename picture parameter set (it's a long packet, not a long write) and
compression mode (it's not a DCS command) enumerations according to the
DSI specification. Order the types according to the spec. Use tabs
instead of spaces for indentation. Use all lower case for hex.

Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191028150047.22048-1-jani.nikula@intel.com