mei: fix compilation error with missing WATCHDOG_CORE

Kconfig is not transitive so INTEL_ME_TXE has to depend
on WATCHDOG_CORE as well

ERROR: "watchdog_unregister_device" [drivers/misc/mei/mei.ko] undefined!
ERROR: "watchdog_register_device" [drivers/misc/mei/mei.ko] undefined!
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/Kconfig

@@ -37,7 +37,7 @@ config INTEL_MEI_ME
 config INTEL_MEI_TXE
 	tristate "Intel Trusted Execution Environment with ME Interface"
 	select INTEL_MEI
-	depends on X86 && PCI
+	depends on X86 && PCI && WATCHDOG_CORE
 	help
 	  MEI Support for Trusted Execution Environment device on Intel SoCs