mmc: vub300: Move away from using deprecated APIs

Suspend and resume of cards are handled by the protocol layer and
consequently the mmc_suspend|resume_host APIs are marked as deprecated.

This means we can simplify the suspend|resume callbacks by removing the
use of the deprecated APIs.

Cc: Tony Olech <tony.olech@elandigitalsystems.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chris Ball <cjb@laptop.org>