greybus: arche-platform: Fix exit path in probe fn

If SVC coldboot fails or if of_platform_populate() fn fails,
then state of device needs to be reverted.

Importantly, if of_platform_populate() fails, then poweroff the SVC.

Testing Done: Tested on DB3.5 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Reviewed-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>