sh: Add support for r0p7734 board

The r0p7734 board has SH7734, 128MB DDR2-SDRAM, USB,
Ethernet, and more.

This patch supports the following functions:
- 128MB DDR2-SDRAM
- 32MB NOR Flash memory
- Serial console (SCIF)
- Ethernet (SH-Ether/SMSC)

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index f796872..f3a84f6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1102,6 +1102,7 @@
 	AP325RXA	SH7723
 	SHMIN		SH7706
 	ECOVEC		SH7724
+	R0P7734     SH7734
 
 Mark Jonas <mark.jonas@de.bosch.com>