dmaengine: shdma: convert to platform device resources

The shdma dmaengine driver currently uses numerous macros to support various
platforms, selected by ifdef's. Convert it to use platform device resources and
lists of channel descriptors to specify register locations, interrupt numbers
and other system-specific configuration variants. Unavoidably, we have to
simultaneously convert all shdma users to provide those resources.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>