vgacon: Add support for setting the default cursor state

Pass the vga cursor state to the vt layer, ensuring that we don't hide
the cursor when the bootloader has deliberately disabled it.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
LKML-Reference: <1258142222-16092-3-git-send-email-mjg@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>