treewide: remove redundant #include <linux/kconfig.h>

Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:

  -include $(srctree)/include/linux/kconfig.h

This commit removes explicit includes except the following:

  * arch/s390/include/asm/facilities_src.h
  * tools/testing/radix-tree/linux/kernel.h

These two are used for host programs.

Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/irqchip/irq-bcm6345-l1.c

@@ -52,7 +52,6 @@
 
 #include <linux/bitops.h>
 #include <linux/cpumask.h>
-#include <linux/kconfig.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>

drivers/irqchip/irq-bcm7038-l1.c

@@ -12,7 +12,6 @@
 #define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt
 
 #include <linux/bitops.h>
-#include <linux/kconfig.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>

drivers/irqchip/irq-bcm7120-l2.c

@@ -13,7 +13,6 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/module.h>
-#include <linux/kconfig.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>

drivers/irqchip/irq-brcmstb-l2.c

@@ -18,7 +18,6 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/module.h>
-#include <linux/kconfig.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/of.h>