Input: lifebook - add CONFIG_DMI dependency

Lifebook protocol can only be activated if we find known DMI signature.
It is useles without DMI.

Reported-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 3feeb3a..c714ca2 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -70,7 +70,7 @@
 config MOUSE_PS2_LIFEBOOK
 	bool "Fujitsu Lifebook PS/2 mouse protocol extension" if EMBEDDED
 	default y
-	depends on MOUSE_PS2 && X86
+	depends on MOUSE_PS2 && X86 && DMI
 	help
 	  Say Y here if you have a Fujitsu B-series Lifebook PS/2
 	  TouchScreen connected to your system.