crypto: api - Move crypto_yield() to algapi.h

It makes no sense for crypto_yield() to be defined in scatterwalk.h ,
move it into algapi.h as it's an internal function to crypto API.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 016c2f1..623a59c 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -410,4 +410,10 @@
 	return __crypto_memneq(a, b, size) != 0UL ? 1 : 0;
 }
 
+static inline void crypto_yield(u32 flags)
+{
+	if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
+		cond_resched();
+}
+
 #endif	/* _CRYPTO_ALGAPI_H */