[POWERPC] 83xx: add base platform support for the mpc8315 rdb board

mpc8315 identical to mpc8313 here, just check compatible.
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/83xx/Kconfig

@@ -7,7 +7,7 @@ config MPC831x_RDB
 	bool "Freescale MPC831x RDB"
 	select DEFAULT_UIMAGE
 	help
-	  This option enables support for the MPC8313 RDB board.
+	  This option enables support for the MPC8313 RDB and MPC8315 RDB boards.
 
 config MPC832x_MDS
 	bool "Freescale MPC832x MDS"

arch/powerpc/platforms/83xx/mpc831x_rdb.c

@@ -64,7 +64,8 @@ static int __init mpc831x_rdb_probe(void)
 {
 	unsigned long root = of_get_flat_dt_root();
 
-	return of_flat_dt_is_compatible(root, "MPC8313ERDB");
+	return of_flat_dt_is_compatible(root, "MPC8313ERDB") ||
+	       of_flat_dt_is_compatible(root, "fsl,mpc8315erdb");
 }
 
 static struct of_device_id __initdata of_bus_ids[] = {