drivers/leds/leds-lp5521.c: provide section tagging

Tag the and remove() function as __devexit respectively.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>