dmaengine: ste_dma40: indicate directions on channels

Since the introduction of the .directions flags, ste_dma40 was
never patched to indicate which transfer directions it can manage.
This causes a problem when trying to use the dmaengine for generic
ALSA SoC DMA:

ux500-msp-i2s.1: Failed to get DMA channel capabilities, falling
   back to period counting: -6

This patch fixes this issue by indicating the supported transfer
directions for slave and memcpy channels.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ste_dma40.c

@@ -2809,12 +2809,14 @@ static void __init d40_chan_init(struct d40_base *base, struct dma_device *dma,
 
 static void d40_ops_init(struct d40_base *base, struct dma_device *dev)
 {
-	if (dma_has_cap(DMA_SLAVE, dev->cap_mask))
+	if (dma_has_cap(DMA_SLAVE, dev->cap_mask)) {
 		dev->device_prep_slave_sg = d40_prep_slave_sg;
+		dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	}
 
 	if (dma_has_cap(DMA_MEMCPY, dev->cap_mask)) {
 		dev->device_prep_dma_memcpy = d40_prep_memcpy;
-
+		dev->directions = BIT(DMA_MEM_TO_MEM);
 		/*
 		 * This controller can only access address at even
 		 * 32bit boundaries, i.e. 2^2