kernel.h: Move lib/cmdline.c prototypes to string.h

The lib/cmdline.c is basically a set of some small string parsers
which are wide used in the kernel. Their prototypes belong to the
string.h rather then kernel.h.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231003130142.2936503-1-andriy.shevchenko@linux.intel.comSigned-off-by: Kees Cook <keescook@chromium.org>

include/linux/kernel.h

@@ -165,12 +165,6 @@ static inline void might_fault(void) { }
 
 void do_exit(long error_code) __noreturn;
 
-extern int get_option(char **str, int *pint);
-extern char *get_options(const char *str, int nints, int *ints);
-extern unsigned long long memparse(const char *ptr, char **retptr);
-extern bool parse_option_str(const char *str, const char *option);
-extern char *next_arg(char *args, char **param, char **val);
-
 extern int core_kernel_text(unsigned long addr);
 extern int __kernel_text_address(unsigned long addr);
 extern int kernel_text_address(unsigned long addr);

include/linux/string.h

@@ -286,9 +286,17 @@ extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
 extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
 
+/* lib/argv_split.c */
 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 extern void argv_free(char **argv);
 
+/* lib/cmdline.c */
+extern int get_option(char **str, int *pint);
+extern char *get_options(const char *str, int nints, int *ints);
+extern unsigned long long memparse(const char *ptr, char **retptr);
+extern bool parse_option_str(const char *str, const char *option);
+extern char *next_arg(char *args, char **param, char **val);
+
 extern bool sysfs_streq(const char *s1, const char *s2);
 int match_string(const char * const *array, size_t n, const char *string);
 int __sysfs_match_string(const char * const *array, size_t n, const char *s);