mmc: SDHI: add SoC specific workaround via HW version

One of Renesas SDHI chip needs workaround to use it, and, we can judge
it based on chip version.  This patch adds very quick-hack workaround
method, since we still don't know how many chips need workaround in
the future.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Chris Ball <cjb@laptop.org>