coresight: etm4x: Update TRCIDR3.NUMPROCS handling to match v4.2

Since ETMv4.2, TRCIDR3.NUMPROCS has been extended to a 5bit field
by encoding the top 2 bits[4:3] in TRCIDR3.[13:12], which were RES0.
Fix the driver to compute the field correctly for ETMv4.2+

Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@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/20201127175256.1092685-6-mathieu.poirier@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -724,8 +724,13 @@ static void etm4_init_arch_data(void *info)
 	else
 		drvdata->sysstall = false;
 
-	/* NUMPROC, bits[30:28] the number of PEs available for tracing */
-	drvdata->nr_pe = BMVAL(etmidr3, 28, 30);
+	/*
+	 * NUMPROC - the number of PEs available for tracing, 5bits
+	 *         = TRCIDR3.bits[13:12]bits[30:28]
+	 *  bits[4:3] = TRCIDR3.bits[13:12] (since etm-v4.2, otherwise RES0)
+	 *  bits[3:0] = TRCIDR3.bits[30:28]
+	 */
+	drvdata->nr_pe = (BMVAL(etmidr3, 12, 13) << 3) | BMVAL(etmidr3, 28, 30);
 
 	/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
 	if (BMVAL(etmidr3, 31, 31))