The platform power states, PLAT_MAX_RET_STATE and PLAT_MAX_OFF_STATE,
can change on Tegra SoCs and so should be defined per-soc.

This patch moves these macro definitions to individual SoC's tegra_def.h
files.

Change-Id: Ib9b2752bc4d79cef6f79bee49882d340f71977a2
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>