rdv3r1: add build support for lcp firmware

Add linker script and cmake files to enable building of LCP runtime
firmware for RD-V3-R1 platform.

Signed-off-by: Pranav Madhu <pranav.madhu@arm.com>
Signed-off-by: Shriram K <shriram.k@arm.com>
Signed-off-by: Nancy . <nancy@arm.com>
Change-Id: I493dc6c5ed55dfd4d2a66b3859202bdd93987958