sh: Add support Renesas Solutions R2D plus board

R2D plus is SH reference board used with SH7751R.
This board has 266Mhz CPU, 64MB SDRAM, Cardbus, CF interface,
one PCI bus, VGA, and two Ethernet controller.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/Makefile b/Makefile
index f985045..420c684 100644
--- a/Makefile
+++ b/Makefile
@@ -2867,6 +2867,11 @@
 	@echo "#define CONFIG_R7780MP 1" >> include/config.h
 	@./mkconfig -a $(@:_config=) sh sh4 r7780mp
 
+r2dplus_config  :   unconfig
+	@ >include/config.h
+	@echo "#define CONFIG_R2DPLUS 1" >> include/config.h
+	@./mkconfig -a $(@:_config=) sh sh4 r2dplus
+
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