[led] Rearrange led backend probing order. MER#1509
[led] Rearrange led backend probing order. MER#1509

Different kinds of led drivers still have similarities in control file
structure.

Do the backend probing in an order that is less likely to produce false
positives.

To ease debugging, elevate logging of backend probe result to notice level.

nemomobile/mce-plugin-libhybris,nemomobile/mce-plugin-libhybris,spiiroin/mce-plugin-libhybris,spiiroin/mce-plugin-libhybris,nemomobile/mce-plugin-libhybris,nemomobile/mce-plugin-libhybris,spiiroin/mce-plugin-libhybris,spiiroin/mce-plugin-libhybris