crypto: caam - fix ERA property reading

In order to ensure that the ERA property is properly read from DT
on all platforms, of_property_read* function needs to be used.

Signed-off-by: Alex Porosanu <alexandru.porosanu@freescale.com>
Signed-off-by: Horia Geant? <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index efacab7..5988237 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -370,14 +370,14 @@
 int caam_get_era(void)
 {
 	struct device_node *caam_node;
-	for_each_compatible_node(caam_node, NULL, "fsl,sec-v4.0") {
-		const uint32_t *prop = (uint32_t *)of_get_property(caam_node,
-				"fsl,sec-era",
-				NULL);
-		return prop ? *prop : -ENOTSUPP;
-	}
+	int ret;
+	u32 prop;
 
-	return -ENOTSUPP;
+	caam_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
+	ret = of_property_read_u32(caam_node, "fsl,sec-era", &prop);
+	of_node_put(caam_node);
+
+	return IS_ERR_VALUE(ret) ? -ENOTSUPP : prop;
 }
 EXPORT_SYMBOL(caam_get_era);