coresight: Add dummy definition for of_coresight_get_cpu()

For !CONFIG_OF case, add a dummy definition for the of_coresight_get_cpu().
Reported-by: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-platform.c

@@ -307,6 +307,11 @@ of_get_coresight_platform_data(struct device *dev,
 {
 	return -ENOENT;
 }
+
+static inline int of_coresight_get_cpu(struct device *dev)
+{
+	return 0;
+}
 #endif
 
 #ifdef CONFIG_ACPI