Tegra186: mce: add the mce_update_cstate_info() helper function

Tegra186: mce: add the mce_update_cstate_info() helper function

This patch adds a helper function to the MCE driver to allow its
clients to issue UPDATE_CSTATE_INFO requests, without having to
setup the CPU context struct.

We introduced a struct to encapsulate the request parameters, that
clients can pass on to the MCE driver. The MCE driver gets the
parameters from the struct and programs the hardware accordingly.

Change-Id: I02bce57506c4ccd90da82127805d6b564375cbf1
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>