Tegra: retrieve power domain tree from the platforms

The platform code generates the power domain tree. The handler to
retrieve the tree should also reside in the platform code.

This patch moves the plat_get_power_domain_tree_desc() to the
individual platforms.

Change-Id: Iaafc83ed381d83129501111ef655e3c58a8a553f
Signed-off-by: Anthony Zhou <anzhou@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
4 files changed