backlight: lm3639: don't mix different enum types

Don't mix different enum types to fix the sparse warnings.

  drivers/video/backlight/lm3639_bl.c:80:51: warning: mixing different enum types
  drivers/video/backlight/lm3639_bl.c:80:51:     int enum lm3639_fleds  versus
  drivers/video/backlight/lm3639_bl.c:80:51:     int enum lm3639_bleds
  drivers/video/backlight/lm3639_bl.c:82:51: warning: mixing different enum types
  drivers/video/backlight/lm3639_bl.c:82:51:     int enum lm3639_fleds  versus
  drivers/video/backlight/lm3639_bl.c:82:51:     int enum lm3639_bleds

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>