reset: Add compile-test stubs

Add stubs for the reset controller registration functions to allow
building reset controller provider drivers with the COMPILE_TEST
Kconfig option enabled.

Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210609112806.3565057-3-thierry.reding@gmail.com


Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>