coresight: etm4x: Handle access to TRCSSPCICRn

coresight: etm4x: Handle access to TRCSSPCICRn

TRCSSPCICR<n> is present only if all of the following are true:
	TRCIDR4.NUMSSCC > n.
	TRCIDR4.NUMPC > 0b0000 .
	TRCSSCSR<n>.PC == 0b1

Add a helper function to check all the conditions.

Link: https://lore.kernel.org/r/20210110224850.1880240-2-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/20210201181351.1475223-4-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>