powerpc: Add printk levels to powernv platform code

Add printk levels to powernv platform code, and convert to
pr_err() etc while here.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index b44eec3..cf85ba8 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -105,12 +105,12 @@
 	if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
 		powerpc_firmware_features |= FW_FEATURE_OPALv2;
 		powerpc_firmware_features |= FW_FEATURE_OPALv3;
-		printk("OPAL V3 detected !\n");
+		pr_info("OPAL V3 detected !\n");
 	} else if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
 		powerpc_firmware_features |= FW_FEATURE_OPALv2;
-		printk("OPAL V2 detected !\n");
+		pr_info("OPAL V2 detected !\n");
 	} else {
-		printk("OPAL V1 detected !\n");
+		pr_info("OPAL V1 detected !\n");
 	}
 
 	/* Reinit all cores with the right endian */