Input: RX51 keymap - fix recent compile breakage

Commit 3fea6026 ("Input: twl40300-keypad - fix handling of "all
ground" rows") broke compilation as I managed to use non-existent
keycodes.

Reported-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>