arm64: Remove custom IRQ stat accounting

Let's switch the arm64 code to the core accounting, which already
does everything we need.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
4 files changed