mmc: omap_hsmmc: Use OMAP_HSMMC_SUPPORTS_DUAL_VOLT flag to remove host->id based hardcoding

Use OMAP_HSMMC_SUPPORTS_DUAL_VOLT flag instead of host->id
for identifying SD bus voltage capabilities.

Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Tested-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>