nvc0: use a different offset for buffers and surfaces

nvc0: use a different offset for buffers and surfaces

To not overwrite buffers and surfaces information, we need to use
a different offset in the driver constant buffer. Currently, OP_SUQ
is only supported for buffers but this will be slightly updated for
images support.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Acked-by: Ilia Mirkin <imirkin@alum.mit.edu>