st/dri: allow both render and sampler compatible dma-buf formats

st/dri: allow both render and sampler compatible dma-buf formats

Currently all the EGL APIs are missing a way to specify how an imported
dma-buf is intended to be used. Demanding the format to be both usable
for sampling and rendering artificially restricts the list of formats a
driver is able to import.

Looking at how the Intel driver implements those DRI2 image APIs it
doesn't distinguish between render or sampler compatible formats. So
this patch aligns behavior between Intel and Gallium based drivers.

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