Tegra: support to set the L2 ECC and Parity enable bit

Tegra: support to set the L2 ECC and Parity enable bit

This patch adds capability to read the boot flag to enable L2 ECC
and Parity Protection bit for the Cortex-A57 CPUs. The previous
bootloader sets this flag value for the platform.

* with some coverity fix:
MISRA C-2012 Directive 4.6
MISRA C-2012 Rule 2.5
MISRA C-2012 Rule 10.3
MISRA C-2012 Rule 10.4

Change-Id: Id7303bbbdc290b52919356c31625847b8904b073
Signed-off-by: Harvey Hsieh <hhsieh@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>