staging: vc04_services: Update testing instructions

Since the initial version of the testing instructions a few
things has changed. So consider the latest arm64/defconfig changes
and the new debugfs entry.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240621131958.98208-11-wahrenst@gmx.net


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>