Add keyboard blink driver

Simple driver that blinks the keyboard LEDs when loaded.  Useful for
checking that the kernel is still alive or for crashdumping

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>