etnaviv: warn when imported TS buffer is the same as color buffer

etnaviv: warn when imported TS buffer is the same as color buffer

Color and TS buffers are allocated separately for each etnaviv resource, so
getting the same base and TS buffer at import time is unexpected and a strong
hint at the application doing something wrong, like passing in the same GEM
handle for all planes on a GBM import. Print a warning to give the user some
feedback.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9780>