nand: Sanitize ONFI strings.

[backport from linux commit 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe]

This is part of the synchronization with the nand driver to the
Linux 3.0 state.

Signed-off-by: Christian Hitz <christian.hitz@aizo.com>
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

include/linux/string.h

@@ -47,6 +47,10 @@ extern char * strchr(const char *,int);
 #ifndef __HAVE_ARCH_STRRCHR
 extern char * strrchr(const char *,int);
 #endif
+extern char * skip_spaces(const char *);
+
+extern char *strim(char *);
+
 #ifndef __HAVE_ARCH_STRSTR
 extern char * strstr(const char *,const char *);
 #endif