Use mce-plugin-libhybris for indicator led control

If mce-plugin-libhybris is installed and support for indicator
led is available, the mce led plugin will utilize it.

[mce] Support led patterns via mce-plugin-libhybris
Merge pull request #54 from spiiroin/leds_via_libhybris

Use mce-plugin-libhybris for indicator led control