mmc: tmio: don't needlessly enable interrupts during probing

We don't have to force-enable MMC interrupts in our .probe() method,
mmc_add_host() will trigger card detection, that will enable all the
necessary interrupts.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>