mmc: mmci: stm32: Check when the voltage switch procedure should be done

mmc: mmci: stm32: Check when the voltage switch procedure should be done

If the card has not been power cycled, it may still be using 1.8V
signaling. This situation is detected in mmc_sd_init_card function and
should be handled in mmci stm32 variant.  The host->pwr_reg variable is
also correctly protected with spin locks.

Fixes: 94b94a93e355 ("mmc: mmci_sdmmc: Implement signal voltage callbacks")
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210701143353.13188-1-yann.gautier@foss.st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>