uboot-imx

ARM: uniphier: split ProXstream2 board data and change DDR frequency

The DDR3 memory chips on ProXstream2 boards support up to 2133 MHz,
while only up to 1866MHz on PH1-LD6b boards.

Split the board data structure and change the DDR frequency of
ProXstream2 boards to 2133 MHz.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>