LinuxKPI: extract stringify() in their own header file

Add linux/stringify.h as directly included by drivers.  Remove the
definitions from compiler.h and include the new header in places
where the stringify macros are already used without linuxkpi.

I have adjusted the Copyright of the new file according to the commit
originaly adding the macros (99e690772a).

Sposnored by:	The FreeBSD Foundation
MFC after:	2 weeks
Reviewed by:	hselasky
Differential Revision: https://reviews.freebsd.org/D30440

sys/compat/linuxkpi/common/include/linux/compiler.h

@@ -60,8 +60,6 @@
 #define	__percpu
 #define	__weak __weak_symbol
 #define	__malloc
-#define	___stringify(...)		#__VA_ARGS__
-#define	__stringify(...)		___stringify(__VA_ARGS__)
 #define	__attribute_const__		__attribute__((__const__))
 #undef __always_inline
 #define	__always_inline			inline

sys/compat/linuxkpi/common/include/linux/kernel.h

@@ -45,6 +45,7 @@
 
 #include <linux/bitops.h>
 #include <linux/compiler.h>
+#include <linux/stringify.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/types.h>

sys/compat/linuxkpi/common/include/linux/module.h

@@ -37,6 +37,7 @@
 
 #include <linux/list.h>
 #include <linux/compiler.h>
+#include <linux/stringify.h>
 #include <linux/kmod.h>
 #include <linux/kobject.h>
 #include <linux/sysfs.h>

sys/compat/linuxkpi/common/include/linux/stringify.h

@@ -0,0 +1,37 @@
+/*-
+ * Copyright (c) 2017 Mellanox Technologies, Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	__LKPI_LINUX_STRINGIFY_H_
+#define	__LKPI_LINUX_STRINGIFY_H_
+
+#include <sys/cdefs.h>
+
+#define	___stringify(...)		#__VA_ARGS__
+#define	__stringify(...)		___stringify(__VA_ARGS__)
+
+#endif	/* __LKPI_LINUX_STRINGIFY_H_ */

sys/compat/linuxkpi/common/include/linux/sysfs.h

@@ -36,6 +36,7 @@
 #include <sys/errno.h>
 
 #include <linux/kobject.h>
+#include <linux/stringify.h>
 
 struct sysfs_ops {
 	ssize_t (*show)(struct kobject *, struct attribute *, char *);