virgl: don't mark buffers as unclean after a write

We can mark the buffer unclean if it's ever bound as a TBO,
SSBO, ABO, or image.

This improves

dEQP-GLES3.performance.buffer.data_upload.function_call.map_buffer_range.new_specified_buffer.flag_write_full.stream_draw

from 9.58 MB/s to 451.17 MB/s.

v2: Track buffer cleanliness as a function of bindings (Ilia).
v3: virgl_modify_clean --> virgl_dirty_res (Erik)

Tested-By: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
(cherry picked from commit 89b4798c)
[Juan A. Suarez: resolve trivial conflicts]
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

Conflicts:
	src/gallium/drivers/virgl/virgl_encode.c