i2c: designware: Make sure the device is suspended before disabling runtime PM

The driver calls pm_runtime_put() right before pm_runtime_disable() in its
->remove() hook to make sure clock is gated etc. However, it turns out that
pm_runtime_put() only calls ->idle() hook without actually suspending
anything. The following pm_runtime_disable() will prevent the driver from
suspending thus leaving it "active".

It is better to suspend the device synchronously to make sure it is
actually suspended before disabling runtime PM from it.

While there, undo call to pm_runtime_use_autosuspend().

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>