mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711

The controller doesn't seem to pick-up on clock changes, so set the
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN flag to query the clock frequency
directly from the clock.

Fixes: f84e411c

 ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711")
Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1628334401-6577-6-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>