drivers/leds/leds-lm3530.c: simplify als configuration on initialization

For better code readability, ALS code is moved to new a function -
lm3530_als_configure()

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>