x86/setup: don't relocate the VGA hole.

x86/setup: don't relocate the VGA hole.

Copying the contents of the VGA hole is at best pointless and at worst
dangerous.  Booting Xen on Xen, it causes a very long delay as each
byte is referred to qemu.

Since we were already discarding the first 1MB of the relocated area,
just avoid copying it in the first place.

Reported-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Signed-off-by: Tim Deegan <tim@xen.org>
Committed-by: Keir Fraser <keir@xen.org>