[Silicon Labs][CMSIS] Patch CMSIS v4.2+ macros into mbed

The current version of cmsis shipping with mbed does not provide the __IOM and friends macros that became standard with CMSIS 4.2+. Patching these into CMSIS to allow vendors to continue updating their support libraries, awaiting a full CMSIS update in mbed (which is past due now).

Author: stevew817

cmsis/core_cm0.h

@@ -197,6 +197,14 @@
 #define     __O     volatile             /*!< Defines 'write only' permissions                */
 #define     __IO    volatile             /*!< Defines 'read / write' permissions              */
 
+#ifdef __cplusplus
+  #define   __IM    volatile             /*!< Defines 'read only' permissions                 */
+#else
+  #define   __IM    volatile const       /*!< Defines 'read only' permissions                 */
+#endif
+#define     __OM    volatile             /*!< Defines 'write only' permissions                */
+#define     __IOM   volatile             /*!< Defines 'read / write' permissions              */
+
 /*@} end of group Cortex_M0 */
 
 

cmsis/core_cm0plus.h

@@ -207,6 +207,14 @@
 #define     __O     volatile             /*!< Defines 'write only' permissions                */
 #define     __IO    volatile             /*!< Defines 'read / write' permissions              */
 
+#ifdef __cplusplus
+  #define   __IM    volatile             /*!< Defines 'read only' permissions                 */
+#else
+  #define   __IM    volatile const       /*!< Defines 'read only' permissions                 */
+#endif
+#define     __OM    volatile             /*!< Defines 'write only' permissions                */
+#define     __IOM   volatile             /*!< Defines 'read / write' permissions              */
+
 /*@} end of group Cortex-M0+ */
 
 

cmsis/core_cm3.h

@@ -202,6 +202,14 @@
 #define     __O     volatile             /*!< Defines 'write only' permissions                */
 #define     __IO    volatile             /*!< Defines 'read / write' permissions              */
 
+#ifdef __cplusplus
+  #define   __IM    volatile             /*!< Defines 'read only' permissions                 */
+#else
+  #define   __IM    volatile const       /*!< Defines 'read only' permissions                 */
+#endif
+#define     __OM    volatile             /*!< Defines 'write only' permissions                */
+#define     __IOM   volatile             /*!< Defines 'read / write' permissions              */
+
 /*@} end of group Cortex_M3 */
 
 

cmsis/core_cm4.h

@@ -248,6 +248,14 @@
 #define     __O     volatile             /*!< Defines 'write only' permissions                */
 #define     __IO    volatile             /*!< Defines 'read / write' permissions              */
 
+#ifdef __cplusplus
+  #define   __IM    volatile             /*!< Defines 'read only' permissions                 */
+#else
+  #define   __IM    volatile const       /*!< Defines 'read only' permissions                 */
+#endif
+#define     __OM    volatile             /*!< Defines 'write only' permissions                */
+#define     __IOM   volatile             /*!< Defines 'read / write' permissions              */
+
 /*@} end of group Cortex_M4 */
 
 

cmsis/core_cm7.h

@@ -263,6 +263,14 @@
 #define     __O     volatile             /*!< Defines 'write only' permissions                */
 #define     __IO    volatile             /*!< Defines 'read / write' permissions              */
 
+#ifdef __cplusplus
+  #define   __IM    volatile             /*!< Defines 'read only' permissions                 */
+#else
+  #define   __IM    volatile const       /*!< Defines 'read only' permissions                 */
+#endif
+#define     __OM    volatile             /*!< Defines 'write only' permissions                */
+#define     __IOM   volatile             /*!< Defines 'read / write' permissions              */
+
 /*@} end of group Cortex_M7 */