ARM: tegra: Expose PM functions required for new cpuidle driver

The upcoming unified CPUIDLE driver will be added to the drivers/cpuidle/
directory and it will require all these exposed Tegra PM-core functions.

Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[treding@nvidia.com: fixup missing include rename]
Signed-off-by: Thierry Reding <treding@nvidia.com>