add rm48x50 bsp and libcpu

We currently only support building with CCS and SCons is not using.
bsp/rm48x50/HALCoGen/HALCoGen.{hcg,dil} is the HALCoGen project file.
You may need to regenerate the source file as you like, providing that:

    1, IRQ is in Dispatch Mode and the table entry is IRQ_Handler. The
    channel 5 in enabled and connected to IRQ.

    2, RTI driver is enabled and compare3 source is selected to counter1
    and the compare3 will generate tick in the period of 10ms. This
    value is coresponding with RT_TICK_PER_SECOND in rtconfig.h.

In CCS, you need to create a new CCS project and create link folders
pointing at bsp/rm48x50, libcpu/arm/rm48x50 and src/, include/. Remember
to add the include path to the Build Properties.

include/rtdef.h

@@ -145,6 +145,14 @@ typedef rt_base_t                       rt_off_t;       /**< Type for offset */
     #define ALIGN(n)                    __declspec(align(n))
     #define rt_inline                   static __inline
     #define RTT_API
+#elif defined (__TI_EABI_SUPPORT__)
+    #define SECTION(x)
+    #define UNUSED
+    #define ALIGN(n)                    
+    #define rt_inline                   static inline
+    #define RTT_API
+#else
+    #error not supported tool chain
 #endif
 
 /* event length */

include/rtthread.h

@@ -19,7 +19,7 @@
 
 #ifndef __RT_THREAD_H__
 #define __RT_THREAD_H__
-
+    #include <stdarg.h>
 #include <rtdef.h>
 #include <rtdebug.h>
 #include <rtservice.h>