nvc0: reserve an area for surfaces info in the driver constbuf

nvc0: reserve an area for surfaces info in the driver constbuf

To process surfaces coordinates from the codegen part, and because
some information like the format is not always available (eg. when
writeonly is used), we have to stick some surfaces data in the
driver constbuf. This is especially true for OpenCL because we don't
know the format at shader compile time.

This bumps the size of each shader area from 1K to 2K.

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