drivers/perf: arm_pmu: make info messages more verbose

On a big.LITTLE system e.g. with Cortex A57 and A53 in case not all cores
are online at PMU probe time we might get

hw perfevents: failed to probe PMU!
hw perfevents: failed to register PMU devices!

making it unclear which cores failed, here.

Add the device tree full name which failed and the error value resulting
in a more verbose and helpful message like

hw perfevents: /soc/pmu_a53: failed to probe PMU! Error -6
hw perfevents: /soc/pmu_a53: failed to register PMU devices! Error -6
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

drivers/perf/arm_pmu.c

@@ -907,7 +907,8 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 	}
 
 	if (ret) {
-		pr_info("failed to probe PMU!\n");
+		pr_info("%s: failed to probe PMU! Error %i\n",
+			node->full_name, ret);
 		goto out_free;
 	}
 
@@ -927,7 +928,8 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 out_destroy:
 	cpu_pmu_destroy(pmu);
 out_free:
-	pr_info("failed to register PMU devices!\n");
+	pr_info("%s: failed to register PMU devices! Error %i\n",
+		node->full_name, ret);
 	kfree(pmu);
 	return ret;
 }