arm64: Add Cortex-X2 CPU part definition

Add the CPU Partnumbers for the new Arm designs.

Cc: Will Deacon <will@kernel.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1642994138-25887-2-git-send-email-anshuman.khandual@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>