sdhci: activate led support also when module

CONFIG_LEDS_CLASS is defined only if led-class is built-in, otherwise
when it is a module the option is called CONFIG_LEDS_CLASS_MODULE. Led
support should also be activated in this case.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>