feat(rdfremont): integrate DTS files for RD-Fremont variants

This update incorporates essential device tree (DTS) files for
RD-Fremont variants. The inclusion covers DTS for platform and config
ID, NT_FW_CONFIG, and TB_FW_CONFIG, enhancing device tree support for
RD-Fremont within the project.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: Ibf898f963d971fe9b07cfa518244c47a8aced81e
4 files changed