trivial sound/parisc updates:

 - substream->dma_device was removed (Stuart Brady)
 - Fix module unloading (Stuart Brady)
 - Fixed the off-by-one in snd_card_harmony_rate_bits (Stuart Brady)
 - Harmony is a GSC device, not available on pure PCI machines (Matthew Wilcox)
 - Fixed module parameter descriptions for ALSA Harmony (Stuart Brady)