dmaengine: kill struct dma_client and supporting infrastructure

All users have been converted to either the general-purpose allocator,
dma_find_channel, or dma_request_channel.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/mmc/host/atmel-mci.c

@@ -55,7 +55,6 @@ enum atmel_mci_state {
 
 struct atmel_mci_dma {
 #ifdef CONFIG_MMC_ATMELMCI_DMA
-	struct dma_client		client;
 	struct dma_chan			*chan;
 	struct dma_async_tx_descriptor	*data_desc;
 #endif