mmc: sdio: support SDIO UHS cards

This patch adds support for sdio UHS cards per the version 3.0
spec.

UHS mode is only enabled for version 3.0 cards when both the
host and the controller support UHS modes.

1.8v signaling support is removed if both the card and the
host do not support UHS.  This is done to maintain
compatibility and some system/card combinations break when
1.8v signaling is enabled when the host does not support UHS.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Aaron Lu <Aaron.lu@amd.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Tested-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>