st/dri: replace format conversion functions with single mapping table

st/dri: replace format conversion functions with single mapping table

Each time I have to touch the buffer import/export functions in the dri
state tracker I get lost in the maze of functions converting between
DRI_IMAGE_FOURCC, DRI_IMAGE_FORMAT, DRI_IMAGE_COMPONENTS and pipe format.

Rip it out and replace by a single table, which defines the correspondence
between the different representations.

Also this now stores all the known representations in the __DRIimageRec,
to avoid the loss of information we currently have when importing a buffer
with a fourcc, which doesn't have a corresponding dri format.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>