Add clocksource id to the ARM generic counter so that it can be easily
identified from callers such as ptp_kvm.
Cc: Mark Rutland
Reviewed-by: Andre Przywara
Signed-off-by: Jianyong Wu
Signed-off-by: Marc Zyngier
Link: https://lore.kernel.org/r/20201209060932.212364-6-jianyong.wu@arm.com