ArmPkg/CpuDxe: order CpuDxe after ArmGicDxe via protocol depex

ArmPkg/CpuDxe: order CpuDxe after ArmGicDxe via protocol depex

Commit 61a7b0ec634f ("ArmPkg/Gic: force GIC driver to run before CPU arch
protocol driver", 2018-02-06) explains why CpuDxe should be dispatched
after ArmGicDxe.

To implement the ordering, we should use a regular protocol depex rather
than the less flexible AFTER opcode. ArmGicDxe installs
gHardwareInterruptProtocolGuid and gHardwareInterrupt2ProtocolGuid as one
of the last actions on its entry point stack; either of those is OK for
CpuDxe to wait for.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Supreeth Venkatesh <Supreeth.Venkatesh@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>