watchdog: Fix SBC8360 dependencies

According to its Kconfig help text, the sbc8360 watchdog driver is
only used on the Axiomtek SBC8360 single-board computer. This piece of
hardware is 32-bit x86 so the driver is useless beyond X86_32.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -835,7 +835,7 @@ config 60XX_WDT
 
 config SBC8360_WDT
 	tristate "SBC8360 Watchdog Timer"
-	depends on X86
+	depends on X86_32
 	---help---
 
 	  This is the driver for the hardware watchdog on the SBC8360 Single