sh: add support for sh7752evb board

The R0P7752C00000RZ board has SH7752, 512MB DDR3-SDRAM, SPI ROM,
Gigabit Ethernet, and eMMC.

This patch supports the following functions:
 - 512MB DDR3-SDRAM, SCIF4, SPI ROM, Gigabit Ethernet, eMMC

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
11 files changed