leds: inconsistent use of EXPORT_SYMBOL_* macros

Hi Linus,

In drivers/leds/led-core.c some symbols are exported with EXPORT_SYMBOL and other with EXPORT_SYMBOL_GPL macros.

It seems that this mess wasn't introduced intentionally, but rather carelessly, as in case of led_blink_set() and led_stop_software_blink() functions, where the former, which enables blinking, is exported with EXPORT_SYMBOL, and the latter, which disables blinking, with EXPORT_SYMBOL_GPL.

It is also worth of noting that all symbols in drivers/led/led-class.c are exported with EXPORT_SYMBOL_GPL, which implies that it is not possible to register LED class device with non-GPL API, which in turn rather eliminates non-GPL users of led-core API.

I'd like just confirm that in this case we are permitted to switch to using EXPORT_SYMBOL_GPL consequently in the LED core.

Best Regards,
Jacek Anaszewski