lib/string_helpers: Split out string_choices.h

Some users may only need the string choice APIs. Split
the respective header, i.e. string_choices.h. Include
it in the string_helpers.h for backward compatibility.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

MAINTAINERS

@@ -8672,6 +8672,7 @@ GENERIC STRING LIBRARY
 R:	Andy Shevchenko <andy@kernel.org>
 S:	Maintained
 F:	include/linux/string.h
+F:	include/linux/string_choices.h
 F:	include/linux/string_helpers.h
 F:	lib/string.c
 F:	lib/string_helpers.c

include/linux/string_choices.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_STRING_CHOICES_H_
+#define _LINUX_STRING_CHOICES_H_
+
+#include <linux/types.h>
+
+static inline const char *str_enable_disable(bool v)
+{
+	return v ? "enable" : "disable";
+}
+
+static inline const char *str_enabled_disabled(bool v)
+{
+	return v ? "enabled" : "disabled";
+}
+
+static inline const char *str_read_write(bool v)
+{
+	return v ? "read" : "write";
+}
+
+static inline const char *str_on_off(bool v)
+{
+	return v ? "on" : "off";
+}
+
+static inline const char *str_yes_no(bool v)
+{
+	return v ? "yes" : "no";
+}
+
+#endif

include/linux/string_helpers.h

@@ -4,6 +4,7 @@
 
 #include <linux/bits.h>
 #include <linux/ctype.h>
+#include <linux/string_choices.h>
 #include <linux/string.h>
 #include <linux/types.h>
 
@@ -113,29 +114,4 @@ void kfree_strarray(char **array, size_t n);
 
 char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n);
 
-static inline const char *str_yes_no(bool v)
-{
-	return v ? "yes" : "no";
-}
-
-static inline const char *str_on_off(bool v)
-{
-	return v ? "on" : "off";
-}
-
-static inline const char *str_enable_disable(bool v)
-{
-	return v ? "enable" : "disable";
-}
-
-static inline const char *str_enabled_disabled(bool v)
-{
-	return v ? "enabled" : "disabled";
-}
-
-static inline const char *str_read_write(bool v)
-{
-	return v ? "read" : "write";
-}
-
 #endif