i965: Add INTEL_DEBUG=tcs,tes and hs,ds flags for tessellation shaders.

i965: Add INTEL_DEBUG=tcs,tes and hs,ds flags for tessellation shaders.

Even though both tessellation shader stages must be used together, I
still think it makes sense to add separate debug flags for each stage.
It makes it possible to read the TCS/HS, rule out problems, then read
the TES/DS separately, without sifting through as much printed text.

I decided to add both the GL names (tcs/tes) and hardware names (hs/ds)
so they can be used interchangeably.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>