If the kernel is running at EL2, the pid of a task is exposed via VMID
instead of the CONTEXTID.  Add support for this in the perf tool.

This patch respects user setting if user has specified any configs
from "contextid", "contextid1" or "contextid2"; otherwise, it
dynamically sets config based on PMU format "contextid".
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: NLeo Yan <leo.yan@linaro.org>
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NMike Leach <mike.leach@linaro.org>
Reviewed-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Link: https://lore.kernel.org/r/20210213113220.292229-4-leo.yan@linaro.org
Link: https://lore.kernel.org/r/20210224164835.3497311-5-mathieu.poirier@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>