ARM: dts: uniphier: add PH1-Pro4 Ace board support

Initial commit for PH1-Pro4 Ace board support.

Note:
There are two variants for the amount of DDR memory; 1GB or 2GB.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>