HID: hid debug from hid-debug.h to hid layer

hid-debug.h contains a lot of code, and should not therefore
be a header.

This patch moves the code to generic hid layer as .c source, and
introduces CONFIG_HID_DEBUG to conditionally compile it, instead
of playing with #define DEBUG and including hid-debug.h.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-core.c

@@ -28,11 +28,11 @@
 #include <linux/input.h>
 #include <linux/wait.h>
 
-#undef DEBUG
 #undef DEBUG_DATA
 
 #include <linux/hid.h>
 #include <linux/hiddev.h>
+#include <linux/hid-debug.h>
 
 /*
  * Version Information