[POWERPC] video & agp: Constify & voidify get_property()

Now that get_property() returns a void *, there's no need to cast its
return value. Also, treat the return value as const, so we can
constify get_property later.

powerpc-specific video & agp driver changes.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

drivers/char/agp/uninorth-agp.c

@@ -601,8 +601,8 @@ static int __devinit agp_uninorth_probe(struct pci_dev *pdev,
 		uninorth_node = of_find_node_by_name(NULL, "u3");
 	}
 	if (uninorth_node) {
-		int *revprop = (int *)
-			get_property(uninorth_node, "device-rev", NULL);
+		const int *revprop = get_property(uninorth_node,
+				"device-rev", NULL);
 		if (revprop != NULL)
 			uninorth_rev = *revprop & 0x3f;
 		of_node_put(uninorth_node);