CMSIS: Move non-config includes behind PTIM ifdef

That is to enabled integration with build-it-all Mbed OS type build
system.

Cherry-picked from CMSIS_5 repo: e8d0a476

Author: bulislaw

rtos/TARGET_CORTEX/rtx5/Source/os_tick_ptim.c

@@ -22,14 +22,14 @@
  * limitations under the License.
  */
 
-#include "os_tick.h"
-#include "irq_ctrl.h"
-
 #include "RTE_Components.h"
 #include CMSIS_device_header
 
 #if defined(PTIM)
 
+#include "os_tick.h"
+#include "irq_ctrl.h"
+
 #ifndef PTIM_IRQ_PRIORITY
 #define PTIM_IRQ_PRIORITY           0xFFU
 #endif
@@ -75,7 +75,7 @@ int32_t OS_Tick_Setup (uint32_t freq, IRQHandler_t handler) {
     }
     prio >>= 1;
   }
-  
+
   // Adjust configured priority to the number of implemented priority bits
   prio = (PTIM_IRQ_PRIORITY << bits) & 0xFFUL;