memory: tegra: Add compile-test stub for tegra_mc_probe_device()

The tegra_mc_probe_device() symbol is only available when the TEGRA_MC
Kconfig option is enabled. Provide a stub if that's not the case so that
the driver can be compile-tested.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210618111846.1286166-1-thierry.reding@gmail.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>