r600g: add initial cayman acceleration support.

r600g: add initial cayman acceleration support.

Cayman is the RadeonHD 69xx series of GPUs. This adds support for
3D acceleration to the r600g driver.

Major changes:
Some context registers moved around - mainly MSAA and clipping/guardband related.
GPR allocation is all dynamic
no vertex cache - all unified in texture cache.
5-wide to 4-wide shader engines (no scalar or trans slot)
	- some changes to how instructions are placed into slots
	- removal of END_OF_PROGRAM bit in favour of END flow control clause
	- no vertex fetch clause - TC accepts vertex or texture

Signed-off-by: Dave Airlie <airlied@redhat.com>