virtio-serial: Remove superfluous serial-* words

These likely were a blind copy-n-paste from hvterm.fs, but they
simply do not make any sense in virtio-serial.fs. The hvterm.fs is
always included from OF.fs, so the serial-* words are globally there.
virtio-serial.fs is only used within the virtio-serial device tree
nodes, to adding the serial-* words there is just superfluous.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

board-qemu/slof/virtio-serial.fs

diff --git a/board-qemu/slof/virtio-serial.fs b/board-qemu/slof/virtio-serial.fs
index 06bfe76..82868e2 100644
--- a/board-qemu/slof/virtio-serial.fs
+++ b/board-qemu/slof/virtio-serial.fs
@@ -90,7 +90,3 @@
 ;
 setup-alias
 
-\ Override serial methods to make term-io.fs happy
-: serial-emit virtio-serial-term-emit ;
-: serial-key? virtio-serial-term-key? ;
-: serial-key  virtio-serial-term-key  ;