[PATCH] sh: Add missing timers directory rule to build

This should have been part of the timer framework support that was merged
earlier, but looks to have been accidentally omitted.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>