Unaligned i/o access on serial UART works on real PCs.
This is used for example by FreeDOS CTMouse driver. Without this it
can't reset and detect serial mice.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/77


Signed-off-by: Arwed Meyer <arwed.meyer@gmx.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220911181840.8933-6-arwed.meyer@gmx.de>