[POWERPC] scsi: 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 scsi driver changes.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/scsi/mac53c94.c b/drivers/scsi/mac53c94.c
index 93edaa8..c77f6f2 100644
--- a/drivers/scsi/mac53c94.c
+++ b/drivers/scsi/mac53c94.c
@@ -431,7 +431,7 @@
 	struct fsc_state *state;
 	struct Scsi_Host *host;
 	void *dma_cmd_space;
-	unsigned char *clkprop;
+	const unsigned char *clkprop;
 	int proplen, rc = -ENODEV;
 
 	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {