libc: Move MB_LEN_MAX from lib_wctob.c to limits.h

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: I3a5addac99adb02f57aba05aa9fe2e6aaf31071d

include/limits.h

@@ -49,7 +49,9 @@
 /********************************************************************************
  * Pre-processor Definitions
  ********************************************************************************/
+
 /* Default values for user configurable limits **********************************/
+
 /* Maximum number of bytes in a filename (not including terminating null). */
 
 #ifndef CONFIG_NAME_MAX
@@ -68,6 +70,13 @@
 #  endif
 #endif
 
+/* Maximum length of any multibyte character in any locale.
+ * We define this value here since the gcc header does not define
+ * the correct value.
+ */
+
+#define MB_LEN_MAX            1
+
 /* Configurable limits required by POSIX ****************************************
  *
  * Required for all implementations:
@@ -303,6 +312,7 @@
 #define SEM_VALUE_MAX  _POSIX_SEM_VALUE_MAX
 
 /* Required for readv() and writev() */
+
 /* There really is no upper limit on the number of vectors */
 
 #define IOV_MAX        INT_MAX