[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>
diff --git a/drivers/video/aty/radeon_pm.c b/drivers/video/aty/radeon_pm.c
index c709176..b9b9396 100644
--- a/drivers/video/aty/radeon_pm.c
+++ b/drivers/video/aty/radeon_pm.c
@@ -1167,7 +1167,7 @@
 			  0x21320032, 0xa1320032, 0x21320032, 0xffffffff,
 			  0x31320032 };
 
-		u32 *mrtable = default_mrtable;
+		const u32 *mrtable = default_mrtable;
 		int i, mrtable_size = ARRAY_SIZE(default_mrtable);
 
 		mdelay(30);
@@ -1186,7 +1186,7 @@
 		if (rinfo->of_node != NULL) {
 			int size;
 
-			mrtable = (u32 *)get_property(rinfo->of_node, "ATY,MRT", &size);
+			mrtable = get_property(rinfo->of_node, "ATY,MRT", &size);
 			if (mrtable)
 				mrtable_size = size >> 2;
 			else