Input: psmouse - make MOUSE_PS2_LIFEBOOK depend on X86

All Fujitsu-Siemens Lifebook systems are x86-based, so we might
as well make MOUSE_PS2_LIFEBOOK depend on X86. This will avoid
surprising things like:

arch/arm/configs/s3c2410_defconfig:CONFIG_MOUSE_PS2_LIFEBOOK=y
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/Kconfig

@@ -70,7 +70,7 @@ config MOUSE_PS2_SYNAPTICS
 config MOUSE_PS2_LIFEBOOK
 	bool "Fujitsu Lifebook PS/2 mouse protocol extension" if EMBEDDED
 	default y
-	depends on MOUSE_PS2
+	depends on MOUSE_PS2 && X86
 	help
 	  Say Y here if you have a Fujitsu B-series Lifebook PS/2
 	  TouchScreen connected to your system.