greybus: arche-apb-ctrl: Remove wake_detect gpio and related code

With TIME_SYNC functionality, assignment of wake/detect pin
will change,
  WD_8A => to bring APB's out of reset
  WD_8B => TIME_SYNC operation

So in order to support this, we can no longer keep wake_detect
gpio in apb-ctrl driver. So remove it.
In the subsequent patches, wake_detect support will be added
to parent SVC driver (arche-platform) who is responsible for SVC control.

Note that, this patch also removes ISR related code.
The APB state still is maintained, for future use.

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