Export MPU Section Attributes (#931)

Export the PRIVILEGED_FUNCTION, PRIVILEGED_DATA, and FREERTOS_SYSTEM_CALL
attributes to make it easier for end users to add their own privileged functions and
system calls.
diff --git a/include/mpu_wrappers.h b/include/mpu_wrappers.h
index 51e7bcf..6117bbb 100644
--- a/include/mpu_wrappers.h
+++ b/include/mpu_wrappers.h
@@ -229,14 +229,6 @@
             #define xStreamBufferReceiveCompletedFromISR    MPU_xStreamBufferReceiveCompletedFromISR
         #endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
 
-/* Remove the privileged function macro, but keep the PRIVILEGED_DATA
- * macro so applications can place data in privileged access sections
- * (useful when using statically allocated objects). */
-        #define PRIVILEGED_FUNCTION
-        #define PRIVILEGED_DATA    __attribute__( ( section( "privileged_data" ) ) )
-        #define FREERTOS_SYSTEM_CALL
-
-
         #if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) )
 
             #define vGrantAccessToTask( xTask, xTaskToGrantAccess )                        vGrantAccessToKernelObject( ( xTask ), ( int32_t ) ( xTaskToGrantAccess ) )
@@ -265,15 +257,12 @@
 
         #endif /* #if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) ) */
 
-    #else /* MPU_WRAPPERS_INCLUDED_FROM_API_FILE */
-
-/* Ensure API functions go in the privileged execution section. */
-        #define PRIVILEGED_FUNCTION     __attribute__( ( section( "privileged_functions" ) ) )
-        #define PRIVILEGED_DATA         __attribute__( ( section( "privileged_data" ) ) )
-        #define FREERTOS_SYSTEM_CALL    __attribute__( ( section( "freertos_system_calls" ) ) )
-
     #endif /* MPU_WRAPPERS_INCLUDED_FROM_API_FILE */
 
+    #define PRIVILEGED_FUNCTION     __attribute__( ( section( "privileged_functions" ) ) )
+    #define PRIVILEGED_DATA         __attribute__( ( section( "privileged_data" ) ) )
+    #define FREERTOS_SYSTEM_CALL    __attribute__( ( section( "freertos_system_calls" ) ) )
+
 #else /* portUSING_MPU_WRAPPERS */
 
     #define PRIVILEGED_FUNCTION