mmc: dw_mmc: fixed wrong regulator_enable in suspend/resume

regulator_enable() was incorrectly placed in the suspend function
instead of the resume function.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>