Sparse reports a warning dma_cookie_t mic_dma_tx_submit_unlock()

warning: context imbalance in  mic_dma_tx_submit_unlock()
	- unexpected unlock

The root cause is the missing annotation at  mic_dma_tx_submit_unlock()
Add the missing annotation __releases(&mic_ch->prep_lock)

Signed-off-by: Jules Irenge <redacted>
---
 drivers/dma/mic_x100_dma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/mic_x100_dma.c b/drivers/dma/mic_x100_dma.c
index fea8608a7810..d15c41151d09 100644
--- a/drivers/dma/mic_x100_dma.c
+++ b/drivers/dma/mic_x100_dma.c

@@ -236,6 +236,7 @@ static inline void mic_dma_update_pending(struct mic_dma_chan *ch)
 }
 
 static dma_cookie_t mic_dma_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
+	__releases(&mic_ch->prep_lock)
 {
 	struct mic_dma_chan *mic_ch = to_mic_dma_chan(tx->chan);
 	dma_cookie_t cookie;

-- 
2.24.1