vga: fix byteswapping.

In case host and guest endianness differ the vga code first creates
a shared surface (using qemu_create_displaysurface_from), then goes
patch the surface format to indicate that the bytes must be swapped.

The switch to pixman broke that hack as the format patching isn't
propagated into the pixman image, so ui code using the pixman image
directly (such as vnc) uses the wrong format.

Fix that by adding a byteswap parameter to
qemu_create_displaysurface_from, so we'll use the correct format
when creating the surface (and the pixman image) and don't have
to patch the format afterwards.

[ v2: unbreak xen build ]

Cc: qemu-stable@nongnu.org
Cc: mark.cave-ayland@ilande.co.uk
Cc: agraf@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1361349432-23884-1-git-send-email-kraxel@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
