ARM: rmobile: Move rcar-gen2-common to rcar-common

To common use of rcar-gen2-common directory in the R-Car SoCs, and change from
rcar-gen2-common to rcar-common.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/board/renesas/porter/Makefile b/board/renesas/porter/Makefile
index dbf32e9..09c07ef 100644
--- a/board/renesas/porter/Makefile
+++ b/board/renesas/porter/Makefile
@@ -7,4 +7,4 @@
 # SPDX-License-Identifier: GPL-2.0
 #
 
-obj-y	:= porter.o qos.o ../rcar-gen2-common/common.o
+obj-y	:= porter.o qos.o ../rcar-common/common.o