Only 7 bits are used for updating the brightness.  (register address :
A0h) So the max_brightness property of lm3530 should be set to 127.

On initializing registers, maximum initial brightness is limited to
'max_brightness'.

Division-by-two is removed on updating the brightness.  This arithmetic is
not necessary because the range of brightness is 0 ~ 127= .
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>