coresight: etm4x: Refactor probing routine

mainline inclusion
from mainline-v5.11-rc5
commit c23bc382
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YCYK
CVE: NA

Reference: https://lore.kernel.org/r/20210110224850.1880240-24-suzuki.poulose@arm.com

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CoreSight ETM with system register access may not have a
memory mapped i/o access. Refactor the ETM specific probing
into a common routine to allow reusing the code for such ETMs.

Link: https://lore.kernel.org/r/20210110224850.1880240-24-suzuki.poulose@arm.com


Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-26-mathieu.poirier@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>