Header cleanup

Change-Id: I84754f316ce940917516cb7f5c59189f523d4095
diff --git a/src/ethosu_common.h b/src/ethosu_common.h
index a5ea197..b22bffd 100644
--- a/src/ethosu_common.h
+++ b/src/ethosu_common.h
@@ -16,14 +16,22 @@
  * limitations under the License.
  */
 
-#if !defined ETHOSU_COMMON_H
+#ifndef ETHOSU_COMMON_H
 #define ETHOSU_COMMON_H
 
+/******************************************************************************
+ * Includes
+ ******************************************************************************/
+
 #include "ethosu55_interface.h"
 #include "ethosu_device.h"
 
 #include <stdio.h>
 
+/******************************************************************************
+ * Defines
+ ******************************************************************************/
+
 #if defined(DRIVER_LOG_SEVERITY) && (DRIVER_LOG_SEVERITY >= LOG_SEVERITY_EMERG)
 #define LOG_EMERG(format, ...)                                                                                         \
     fprintf(stderr, format, ##__VA_ARGS__);                                                                            \
@@ -97,6 +105,10 @@
 #define MASK_0_31_BITS (0xFFFFFFFF)
 #define MASK_32_47_BITS (0xFFFF00000000)
 
+/******************************************************************************
+ * Inline functions
+ ******************************************************************************/
+
 static const __attribute__((section("npu_driver_version"))) char driver_version_str[] = VER_STR(
     ETHOSU_DRIVER_VERSION_MAJOR) "." VER_STR(ETHOSU_DRIVER_VERSION_MINOR) "." VER_STR(ETHOSU_DRIVER_VERSION_PATCH);