Add support for AMD Pensando Elba SoC which explicitly
controls byte-lane enables on writes.

Select MMC_SDHCI_IO_ACCESSORS for MMC_SDHCI_CADENCE which
allows Elba SoC sdhci_elba_ops to overwrite the SDHCI
IO memory accessors
Signed-off-by: Brad Larson <blarson@amd.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230410184526.15990-14-blarson@amd.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>