intel: Make a wrapper for intelEmitCopyBlit using miptrees.

intel: Make a wrapper for intelEmitCopyBlit using miptrees.

I had previously asserted that it was hard to write a useful, simpler
blit function, but I think this might be it.

This has the side effect of extending the 32k pitch check to a few more
places that were missing it.

v2: Update comment for being moved inside intel_miptree_blit().

Reviewed-and-tested-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Paul Berry <stereotype441@gmail.com>