rdv3r1: add build support for mcp firmware

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

Signed-off-by: Nancy . <nancy@arm.com>
Signed-off-by: Lokesh B V <Lokesh.BV@Arm.com>
Change-Id: Iec87a10e0d310cc91665aa1760c59eac1e93a8ae