[libc] remove rtlibc

libcpu/mips/common/ptrace.h

@@ -63,7 +63,7 @@ struct pt_regs {
      * so it should be a part of pt_regs */
     struct mips_fpu_struct fpu;
 #endif
-} __aligned(8);
+} __attribute__((aligned(8)));
 #endif
 
 /* Note: For call stack o32 ABI has 0x8 shadowsoace Here  */

libcpu/risc-v/virt64/cpuport.c

@@ -9,13 +9,13 @@
  * 2021-02-11     lizhirui     add gp support
  */
 
+#include <stddef.h>
 #include <rthw.h>
 #include <rtthread.h>
 
 #include "cpuport.h"
 #include "stack.h"
 
-
 /**
  * @brief from thread used interrupt context switch
  *