drivers/dma: remove unused support for MEMSET operations

There have never been any real users of MEMSET operations since they
have been introduced in January 2007 by commit 7405f74bad ("dmaengine:
refactor dmaengine around dma_async_tx_descriptor").  Therefore remove
support for them for now, it can be always brought back when needed.

[sebastian.hesselbarth@gmail.com: fix drivers/dma/mv_xor]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Olof Johansson <olof@lixom.net>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/dma/dmaengine.c

@@ -663,11 +663,6 @@ static bool device_has_all_tx_types(struct dma_device *device)
 		return false;
 	#endif
 
-	#if defined(CONFIG_ASYNC_MEMSET) || defined(CONFIG_ASYNC_MEMSET_MODULE)
-	if (!dma_has_cap(DMA_MEMSET, device->cap_mask))
-		return false;
-	#endif
-
 	#if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
 	if (!dma_has_cap(DMA_XOR, device->cap_mask))
 		return false;
@@ -729,8 +724,6 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_pq);
 	BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
 		!device->device_prep_dma_pq_val);
-	BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
-		!device->device_prep_dma_memset);
 	BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
 		!device->device_prep_dma_interrupt);
 	BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&