tee: Add probe, remove and shutdown bus callbacks to tee_client_driver
Introduce a bus specific probe, remove and shutdown function. For now
this only allows to get rid of a cast of the generic device to a
tee_client device in the drivers and changes the remove prototype to
return void---a non-zero return value is ignored anyhow.
The objective is to get rid of users of struct device_driver callbacks
.probe(), .remove() and .shutdown() to eventually remove these. Until
all tee_client drivers are converted this results in a runtime warning
about the drivers needing an update because there is a bus probe
function and a driver probe function.