pckbd: remove duplicated keyboard and mouse defines

In 2005 the author of commit daa57963 "PS2 mouse and keyboard
separation (Paul Brook)" and 0e43e99c "PS2 mouse and keyboard
separation (Paul Brook)" separated the PS/2 controller code and
the PS/2 keyboard and mouse code. It seems he forgot to remove
a few defines. Remove them now.

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20210525181441.27768-11-vr_qemu@t-online.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>