crypto: omap-aes - Use pm_runtime_put instead of pm_runtime_put_sync in tasklet

After DMA is complete, the omap_aes_finish_req function is called as
a part of the done_task tasklet. During this its atomic and any calls
to pm functions should not assume they wont sleep.

The patch replaces a call to pm_runtime_put_sync (which can sleep) with
pm_runtime_put thus fixing a kernel panic observed on AM33xx SoC during
AES operation.

Tested on an AM33xx SoC device (beaglebone board).
To reproduce the problem, I used the tcrypt kernel module as:
modprobe tcrypt sec=2 mode=500
Signed-off-by: NJoel A Fernandes <joelagnel@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-aes.c

@@ -636,7 +636,7 @@ static void omap_aes_finish_req(struct omap_aes_dev *dd, int err)
 
 	pr_debug("err: %d\n", err);
 
-	pm_runtime_put_sync(dd->dev);
+	pm_runtime_put(dd->dev);
 	dd->flags &= ~FLAGS_BUSY;
 
 	req->base.complete(&req->base, err);