ACPICA: Add RISC-V PLIC APIC structure in MADT

ACPICA commit 2756c6ed68d6850da35e65f16c489985995f28d7

RISC-V PLIC is a platform interrupt controller for
handling wired interrupt in a RISC-V systems.
Add its structure definition in the MADT table.

Link: https://github.com/acpica/acpica/commit/2756c6ed


Signed-off-by: Haibo, Xu <haibo1.xu@intel.com>
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>