Blackfin: fix DMA/cache bug when resuming from suspend to RAM

The dma_memcpy() function takes care of flushing different caches for us.
Normally this is what we want, but when resuming from mem, we don't yet
have caches enabled.  If these functions happen to be placed into L1 mem
(which is what we're trying to relocate), then things aren't going to
work.  So define a non-cache dma_memcpy() variant to utilize in situations
like this.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>