kernel.h: split the hexadecimal related helpers to hex.h

For the sake of cleaning up the kernel.h split the hexadecimal related
helpers to own header called 'hex.h'.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Andy Shevchenko <[e-mail]>
Cc: Rasmus Villemoes <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

include/linux/hex.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_HEX_H
+#define _LINUX_HEX_H
+
+#include <linux/types.h>
+
+extern const char hex_asc[];
+#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *hex_byte_pack(char *buf, u8 byte)
+{
+	*buf++ = hex_asc_hi(byte);
+	*buf++ = hex_asc_lo(byte);
+	return buf;
+}
+
+extern const char hex_asc_upper[];
+#define hex_asc_upper_lo(x)	hex_asc_upper[((x) & 0x0f)]
+#define hex_asc_upper_hi(x)	hex_asc_upper[((x) & 0xf0) >> 4]
+
+static inline char *hex_byte_pack_upper(char *buf, u8 byte)
+{
+	*buf++ = hex_asc_upper_hi(byte);
+	*buf++ = hex_asc_upper_lo(byte);
+	return buf;
+}
+
+extern int hex_to_bin(unsigned char ch);
+extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
+extern char *bin2hex(char *dst, const void *src, size_t count);
+
+bool mac_pton(const char *s, u8 *mac);
+
+#endif

include/linux/kernel.h

···
 #include <linux/compiler.h>
 #include <linux/container_of.h>
 #include <linux/bitops.h>
+#include <linux/hex.h>
 #include <linux/kstrtox.h>
 #include <linux/log2.h>
 #include <linux/math.h>
···
 	SYSTEM_RESTART,
 	SYSTEM_SUSPEND,
 } system_state;
-
-extern const char hex_asc[];
-#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
-#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
-
-static inline char *hex_byte_pack(char *buf, u8 byte)
-{
-	*buf++ = hex_asc_hi(byte);
-	*buf++ = hex_asc_lo(byte);
-	return buf;
-}
-
-extern const char hex_asc_upper[];
-#define hex_asc_upper_lo(x)	hex_asc_upper[((x) & 0x0f)]
-#define hex_asc_upper_hi(x)	hex_asc_upper[((x) & 0xf0) >> 4]
-
-static inline char *hex_byte_pack_upper(char *buf, u8 byte)
-{
-	*buf++ = hex_asc_upper_hi(byte);
-	*buf++ = hex_asc_upper_lo(byte);
-	return buf;
-}
-
-extern int hex_to_bin(unsigned char ch);
-extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
-extern char *bin2hex(char *dst, const void *src, size_t count);
-
-bool mac_pton(const char *s, u8 *mac);
 
 /*
  * General tracing related utility functions - trace_printk(),