rdv3r1cfg1: add model startup support for RD-V3-R1-Cfg1 platform

Added initial model startup support for RD-V3-R1-Cfg1 platform.
The RD-V3-R1-Cfg1 platform is the quad chiplets platforms.
Added support for uefi, busybox, buildroot tests.

RD-V3-R1-Cfg1 now have PCIe enabled. PCIe is needed to enable distro boot.
Added the RD-V3-R1 to the disto boot supported platforms in the config.

Signed-off-by: Lokesh B V <Lokesh.BV@Arm.com>
Change-Id: I4808977d86d2b3325271bc3ad015ac90b6176d24