leds: update LP552x support Kconfig and Makefile

Provide configuration and compilation support for LP5521 and LP5523

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>