mmc: tmio: postpone controller reset during resume

When resuming, the tmio_mmc_host_resume() function is run when the
controller might still be powered down. Issuing a reset command to it at
that time has no effect. This patch postpones resetting the controller
until the first powering-up .set_ios() call.

Reported-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>