svga: Support accelerated conditional blitting

svga: Support accelerated conditional blitting

The blitter has functions to save and restore the conditional rendering state,
but we currently don't save the needed info.

Since also the copy_region_vgpu10 path supports conditional blitting,
we instead use the same function as the clearing routines and move
that function to svga_pipe_query.c

Note that we still haven't implemented conditional blitting with
the software fallbacks.

Fixes piglit nv_conditional_render::copyteximage

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>