dma: Make the 'mask' parameter of __dma_request_channel const

The 'mask' parameter is not modified in __dma_request_channel and really
shouldn't be. Make this explicit by making the parameter const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 91ac8da..dd6d21b 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -967,7 +967,8 @@
 #ifdef CONFIG_DMA_ENGINE
 enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
 void dma_issue_pending_all(void);
-struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
+struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
+					dma_filter_fn fn, void *fn_param);
 struct dma_chan *dma_request_slave_channel(struct device *dev, char *name);
 void dma_release_channel(struct dma_chan *chan);
 #else
@@ -978,7 +979,7 @@
 static inline void dma_issue_pending_all(void)
 {
 }
-static inline struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask,
+static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 					      dma_filter_fn fn, void *fn_param)
 {
 	return NULL;
@@ -1005,9 +1006,9 @@
 	__dma_request_slave_channel_compat(&(mask), x, y, dev, name)
 
 static inline struct dma_chan
-*__dma_request_slave_channel_compat(dma_cap_mask_t *mask, dma_filter_fn fn,
-				  void *fn_param, struct device *dev,
-				  char *name)
+*__dma_request_slave_channel_compat(const dma_cap_mask_t *mask,
+				  dma_filter_fn fn, void *fn_param,
+				  struct device *dev, char *name)
 {
 	struct dma_chan *chan;