greybus: arche-platform: Cancel delayed_work in driver remove fn

This is a bug fix, where as part of cleanup, delayed work was not
canceled in driver remove function. So fix it.

Testing Done: Tested on EVT1.2 and DB3.5 platform.

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