mmc: core: Support UHS-II card control and access

Embed UHS-II access/control functionality into the MMC request
processing flow.

Signed-off-by: Jason Lai <jason.lai@genesyslogic.com.tw>
Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
Message-ID: <20241018105333.4569-2-victorshihgli@gmail.com>
[Ulf: A couple of cleanups and fixed sd_uhs2_power_off()]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>