async_tx: replace 'int_en' with operation preparation flags

Pass a full set of flags to drivers' per-operation 'prep' routines.
Currently the only flag passed is DMA_PREP_INTERRUPT.  The expectation is
that arch-specific async_tx_find_channel() implementations can exploit this
capability to find the best channel for an operation.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Reviewed-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index 5bcfc55..dff38ac 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -701,7 +701,7 @@
 						dma_addr_t dma_dest,
 						dma_addr_t dma_src,
 						size_t len,
-						int int_en)
+						unsigned long flags)
 {
 	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 	struct ioat_desc_sw *new;
@@ -724,7 +724,7 @@
 						dma_addr_t dma_dest,
 						dma_addr_t dma_src,
 						size_t len,
-						int int_en)
+						unsigned long flags)
 {
 	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 	struct ioat_desc_sw *new;