Tegra186: support for C6/C7 CPU_SUSPEND states

Tegra186: support for C6/C7 CPU_SUSPEND states

This patch adds support for the C6 and C7 CPU_SUSPEND states. C6 is
an idle state while C7 is a powerdown state.

The MCE block takes care of the entry/exit to/from these core power
states and hence we call the corresponding MCE handler to process
these requests. The NS driver passes the tentative time that the
core is expected to stay in this state as part of the power_state
parameter, which we store in a per-cpu array and pass it to the
MCE block.

Change-Id: I152acb11ab93d91fb866da2129b1795843dfa39b
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>