RGMP 4.0 update from Qiang Yu

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5305 42af7a65-404d-4744-a932-0658087f49c3

lib/Kconfig

@@ -223,6 +223,13 @@ config MEMSET_64BIT
 		Compiles memset() for architectures that suppport 64-bit operations
 		efficiently.
 
+config ARCH_STRCHR
+	bool "strchr()"
+	default n
+	---help---
+		Select this option if the architecture provides an optimized version
+		of strchr().
+
 config ARCH_STRCMP
 	bool "strcmp()"
 	default n

lib/string/lib_strchr.c

@@ -59,6 +59,7 @@
  *
  ****************************************************************************/
 
+#ifndef CONFIG_ARCH_STRCHR
 FAR char *strchr(FAR const char *s, int c)
 {
   if (s)
@@ -74,3 +75,4 @@ FAR char *strchr(FAR const char *s, int c)
 
   return NULL;
 }
+#endif