lib, vsprintf: introduce strict_strtoul

as checkpatch proposes to use strict_strtoul instead of
simple_strtoul, introduce it.

Ported this function from Linux 2.6.38 commit ID:
521cb40b0c44418a4fd36dc633f575813d59a43d

Signed-off-by: Heiko Schocher <hs@denx.de>
cc: Wolfgang Denk <wd@denx.de>
cc: Detlev Zundel <dzu@denx.de>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>

include/_exports.h

diff --git a/include/_exports.h b/include/_exports.h
index d89b65b..349a3c5 100644
--- a/include/_exports.h
+++ b/include/_exports.h
@@ -19,6 +19,7 @@
 EXPORT_FUNC(getenv)
 EXPORT_FUNC(setenv)
 EXPORT_FUNC(simple_strtoul)
+EXPORT_FUNC(strict_strtoul)
 EXPORT_FUNC(simple_strtol)
 EXPORT_FUNC(strcmp)
 EXPORT_FUNC(i2c_write)

include/common.h

diff --git a/include/common.h b/include/common.h
index 00e266e..1e4a6a5 100644
--- a/include/common.h
+++ b/include/common.h
@@ -650,6 +650,7 @@
 
 /* lib/vsprintf.c */
 ulong	simple_strtoul(const char *cp,char **endp,unsigned int base);
+int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 unsigned long long	simple_strtoull(const char *cp,char **endp,unsigned int base);
 long	simple_strtol(const char *cp,char **endp,unsigned int base);
 void	panic(const char *fmt, ...)

include/exports.h

diff --git a/include/exports.h b/include/exports.h
index ddd1bf4..e14d727 100644
--- a/include/exports.h
+++ b/include/exports.h
@@ -20,6 +20,7 @@
 unsigned long get_timer(unsigned long);
 int vprintf(const char *, va_list);
 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base);
+int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 char *getenv (char *name);
 int setenv (char *varname, char *varvalue);
 long simple_strtol(const char *cp,char **endp,unsigned int base);