Commit 20b92a30 ("mmc: sdhci: update signal voltage switch code")
removed voltage switch delays from sdhci because mmc core had been
enhanced to support them. However that assumed that sdhci_set_ios()
did a single clock change, which it did not, and so the delays in mmc
core, which should have come after the first clock change, were not
effective.

Fix by avoiding re-configuring UHS and preset settings when the clock
is turning on and the settings have not changed. That then also avoids
the associated clock changes, so that then sdhci_set_ios() does a single
clock change when voltage switching, and the mmc core delays become
effective.

To do that has meant keeping track of driver strength (host->drv_type),
and cases of reinitialization (host->reinit_uhs).

Note also, the 'turning_on_clk' restriction should not be necessary
but is done to minimize the impact of the change on stable kernels.

Fixes: 20b92a30 ("mmc: sdhci: update signal voltage switch code")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20221128133259.38305-2-adrian.hunter@intel.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>