v3dv: increase number of supported SSBOs

v3dv: increase number of supported SSBOs

Some CTS tests use more than what we expose and other drivers
also seem to be exposing many more than us (in the order of thousands).
I don't think we want to expose a very large number since we use this
limit to size some arrays in the driver, but bumping it a bit over the
minimum of 4 required by the spec might be reasonable.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11159>