dmaengine: qcom_hidma: remove unused code

Fix the following clang warning:

drivers/dma/qcom/hidma.c:94:20: warning: unused function 'to_hidma_desc'
[-Wunused-function].
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/1617270816-36400-1-git-send-email-jiapeng.chong@linux.alibaba.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/qcom/hidma.c

@@ -90,12 +90,6 @@ static inline struct hidma_chan *to_hidma_chan(struct dma_chan *dmach)
 	return container_of(dmach, struct hidma_chan, chan);
 }
 
-static inline
-struct hidma_desc *to_hidma_desc(struct dma_async_tx_descriptor *t)
-{
-	return container_of(t, struct hidma_desc, desc);
-}
-
 static void hidma_free(struct hidma_dev *dmadev)
 {
 	INIT_LIST_HEAD(&dmadev->ddev.channels);