armv8: Enable tasks stats for iotop

Created by: nbuchwitz

Tools like iotop cannot show IO utilization unless task stats are enabled. The options are present in our other revpi defconfigs, so the missing options in v8 are most likely related to https://github.com/RevolutionPi/linux/commit/99ab277abdc289fd1e491e981687f0616479353d, which removed CONFIG KVM (depends on the task stat options).

Signed-off-by: Nicolai Buchwitz n.buchwitz@kunbus.com