drm/radeon: prepare header files for drmP.h removal

While removing drmP.h from all .c files the list of
header files are also sorted alphabetically.
To allow this adjust the header files to pull in
the dependencies they needed to allow this.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190608080241.4958-6-sam@ravnborg.org