drivers: dma: Mark functions as static in dma_v3.c

Mark the functions ioat3_prep_xor_val(), ioat3_prep_pq_val() and
ioat3_prep_pqxor_val() as static in dma_v3.c because they are not used
outside this file.

This eliminates the following warnings in dma_v3.c:
drivers/dma/ioat/dma_v3.c:741:1: warning: no previous prototype for ‘ioat3_prep_xor_val’ [-Wmissing-prototypes]
drivers/dma/ioat/dma_v3.c:1092:1: warning: no previous prototype for ‘ioat3_prep_pq_val’ [-Wmissing-prototypes]
drivers/dma/ioat/dma_v3.c:1134:1: warning: no previous prototype for ‘ioat3_prep_pqxor_val’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/ioat/dma_v3.c

@@ -740,7 +740,7 @@ ioat3_prep_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 	return __ioat3_prep_xor_lock(chan, NULL, dest, src, src_cnt, len, flags);
 }
 
-struct dma_async_tx_descriptor *
+static struct dma_async_tx_descriptor *
 ioat3_prep_xor_val(struct dma_chan *chan, dma_addr_t *src,
 		    unsigned int src_cnt, size_t len,
 		    enum sum_check_flags *result, unsigned long flags)
@@ -1091,7 +1091,7 @@ ioat3_prep_pq(struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
 	}
 }
 
-struct dma_async_tx_descriptor *
+static struct dma_async_tx_descriptor *
 ioat3_prep_pq_val(struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src,
 		  unsigned int src_cnt, const unsigned char *scf, size_t len,
 		  enum sum_check_flags *pqres, unsigned long flags)
@@ -1133,7 +1133,7 @@ ioat3_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src,
 				     flags);
 }
 
-struct dma_async_tx_descriptor *
+static struct dma_async_tx_descriptor *
 ioat3_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
 		     unsigned int src_cnt, size_t len,
 		     enum sum_check_flags *result, unsigned long flags)