ARM: tegra: Compile sleep-tegra20/30.S unconditionally

ARM: tegra: Compile sleep-tegra20/30.S unconditionally

The sleep-tegra*.S provides functionality required for suspend/resume
and CPU hotplugging. The new unified CPUIDLE driver will support multiple
hardware generations starting from Terga20 and ending with Tegra124, the
driver will utilize functions that are provided by the assembly and thus
it is cleaner to compile that code without any build-dependencies in order
to avoid churning with #ifdef's.

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>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>