Remove the blink driver

Yeah, we could have just disabled it, but there's work on a new one that
isn't as fundamentally broken, so there really doesn't seem to be any
point in keeping it around.

The recent timer cleanup broke the only valid use, and when I say
"valid", I obviously mean "totally broken".  So it's not like it works,
or really even can work in the current format that uses the unsafe
"panic" LED blinking routines..

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>