i965: Fix issues with number of VS URB entries on Cherryview/Broxton.
Cherryview/Broxton annoyingly have a minimum number of VS URB entries
of 34, which is not a multiple of 8. When the VS size is less than 9,
the number of VS entries has to be a multiple of 8.
Notably, BLORP programmed the minimum number of VS URB entries (34), with
a size of 1 (less than 9), which is invalid.
It seemed like this could be a problem in the regular URB code as well,
so I went ahead and updated that to be safe.
Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>