Andi Kleen points out that the intel-agp driver actually works on i865's, where
the -mch driver doesn't.  The -mch driver was something of a failed experiment.
Hoping that the code would be much cleaner, I forked the intel-agp driver into
this variant, and removed some legacy bits. The result was a third the size,
but it still was no work of art, worse yet -- it didn't even do what it said on the can.

intel-agp still supports everything that the -mch driver did, so we can just
remove this from the tree and fall back to the old driver.
Signed-off-by: Dave Jones <davej@redhat.com>