cert_create: updated tool for platform defined certs, keys & extensions

Changes to 'tools/cert_create' folder, to include platform defined
certificates, keys, and extensions.

NXP SoC lx2160a : based platforms requires additional
FIP DDR to be loaded before initializing the DDR.

To enable chain of trust on these platforms, FIP DDR
image needs to be authenticated, additionally.

Platform specific folder 'tools/nxp/cert_create_helper'
is added to support platform specific macros and definitions.

Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: I4752a30a9ff3aa1d403e9babe3a07ba0e6b2bf8f
15 files changed