Tegra: drivers: memctrl: introduce function to secure on-chip TZRAM

Tegra: drivers: memctrl: introduce function to secure on-chip TZRAM

This patch introduces a function to secure the on-chip TZRAM memory. The
Tegra132 and Tegra210 chips do not have a compelling use case to lock the
TZRAM. The trusted OS owns the TZRAM aperture on these chips and so it
can take care of locking the aperture. This might not be true for future
chips and this patch makes the TZRAM programming flexible.

Change-Id: I3ac9f1de1b792ccd23d4ded274784bbab2ea224a
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>