HID: replace offsets values with their corresponding BTN_* defines

Instead of using magic values, use their corresponding BTN_* defines
from linux/input.h.

Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index c075782..e60fdb8 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -319,21 +319,21 @@
 
 		switch (field->application) {
 		case HID_GD_MOUSE:
-		case HID_GD_POINTER:  code += 0x110; break;
+		case HID_GD_POINTER:  code += BTN_MOUSE; break;
 		case HID_GD_JOYSTICK:
 				if (code <= 0xf)
 					code += BTN_JOYSTICK;
 				else
 					code += BTN_TRIGGER_HAPPY;
 				break;
-		case HID_GD_GAMEPAD:  code += 0x130; break;
+		case HID_GD_GAMEPAD:  code += BTN_GAMEPAD; break;
 		default:
 			switch (field->physical) {
 			case HID_GD_MOUSE:
-			case HID_GD_POINTER:  code += 0x110; break;
-			case HID_GD_JOYSTICK: code += 0x120; break;
-			case HID_GD_GAMEPAD:  code += 0x130; break;
-			default:              code += 0x100;
+			case HID_GD_POINTER:  code += BTN_MOUSE; break;
+			case HID_GD_JOYSTICK: code += BTN_JOYSTICK; break;
+			case HID_GD_GAMEPAD:  code += BTN_GAMEPAD; break;
+			default:              code += BTN_MISC;
 			}
 		}