mmc: mtk-sd: Take action for no-sdio device-tree parameter

This driver was unconditionally enabling support for SDIO mode,
but we do have a generic "no-sdio" DT parameter that sets caps2
MMC_CAP2_NO_SDIO.

Modify the HW initialization sequence to enable SDIO support only
if it hasn't been explicitly disabled in device-tree.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20211216125748.179602-3-angelogioacchino.delregno@collabora.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>