HP-WMI: additional keycode (or typo)

On my HP 2510, pressing the (i) button generates an unknown keycode:
0x213b. So here is a patch adding support for it. However, as it seems
there is already support for a similar button connected to 0x231b as
keycode, I wonder if it could be a typo in the driver?

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>