arm: rmobile: Add support gose board

The gose board has R8A7793, 1GB DDR3-SDRAM, USB, Ethernet, and more.
This patch supports the following functions:
- DDR3-SDRAM
- SCIF
- QSPI
- SPI

Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
CC: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>