dma: convert dma_devclass to use dev_groups
dma: convert dma_devclass to use dev_groups

The dev_attrs field of struct class is going away soon, dev_groups
should be used instead.  This converts the dma dma_devclass code to use
the correct field.

Cc: Dan Williams <6291f50c5c0e88707a6118c214e5c12d843a54d6@fb.com>
Acked-by: Vinod Koul <5cf69c63beb17bf38d63aa0e923ee8256af0e205@intel.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs