platform/x86: asus-wmi: Update unknown code message

Prepend 0x to the actual key code to specify it
is already an hex value

Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com>
Link: https://lore.kernel.org/r/20220506122536.113566-1-luca.stefani.ge1@gmail.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>