i965/msaa: Modify blorp code to account for Gen7 MSAA layouts.

i965/msaa: Modify blorp code to account for Gen7 MSAA layouts.

Since blorp uses color textures and render targets to do all its work
(even when blitting stencil and depth data), it always has to
configure the Gen7 GPU to use the new "sliced" MSAA layout.  However,
when blitting stencil or depth data, the actual MSAA layout is
interleaved (as in Gen6).  Therefore, blorp has to do extra coordinate
transformation work to account for the interleaving manually.

This patch causes blorp to perform the necessary extra coordinate
transformations.

It also modifies the blorp SURFACE_STATE setup code for Gen7, so that
it does not try to correct the surface width and height to account for
MSAA, since "sliced" MSAA layout doesn't affect the surface width or
height.

Acked-by: Kenneth Graunke <kenneth@whitecape.org>