mmc: sdhci-iproc: Add support for the legacy sdhci controller on the BCM7211

Add support for the legacy Arasan sdhci controller on the BCM7211 and
related SoC's. This includes adding a .shutdown callback to increase
the power savings during S5.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Link: https://lore.kernel.org/r/20210602192758.38735-2-alcooperx@gmail.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>