mmc: tmio: sdhi: Configure DT2FF register for HS400 mode

The DT2FF register must be configured differently for HS400 mode
and for HS200/SDR104 mode. Configure the DT2FF register according
to the recommended datasheet settings for each mode.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>