ARM: ux500: bump MMC/SD max frequency for DT boots

In patch:
"ARM: ux500: Enable 100MHz for SD/SDIO/MMC devices"
the max frequency for the MMC/SD/SDIO adapters was
increased from 50 to 100MHz. Do the same for the
device tree boot path.

Cc: Lee Jones <lee.jones@linaro.org>
Cc: Gabriel Fernandez <gabriel.fernandez.st@gmail.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>