From: Joey Gouly <joey.gouly@arm.com>
Subject: [PATCH v2 1/1] ShellPkg: Validate that the Boot CPU is present in MADT

The ACPI 6.3 Specification, January 2019, section 5.2.12.14 states that
the firmware must convey each processor’s GIC information to the OS using
the GICC structure.

If a GICC structure for the boot CPU is missing some standards-based
operating system may crash with an error code. It may be difficult to
diagnose the reason for the crash as the error code may be too generic
and mean firmware error.

Therefore add validation to the MADT table parser to check that a GICC is
present for the boot CPU.