feat(neoverse-rd): add a routine to update NT_FW_CONFIG in BL31

In the BL1 based boot-flow, the non-secure DTB, NT_FW_CONFIG, is parsed
in BL2. As BL1 and BL2 are not part of RESET_TO_BL31, add support to
parse and configure this DTB in BL31. NT_FW_CONFIG contains the platform
information which is needed by BL33.

Signed-off-by: Rakshit Goyal <rakshit.goyal@arm.com>
Signed-off-by: Vivek Gautam <vivek.gautam@arm.com>
Change-Id: Ib1fb5417c36523eb2ec02aa22845218de68809aa
4 files changed