[media] lmedm04: NEC scancode cleanup

This changes the keymap back to the state before commit 616a4b83
and changes the driver to use full NEC32 scancodes following the
instructions provided by Malcolm Priestley <tvboxspy@gmail.com>.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>