thermal: kirkwood: allow compile test

Adding COMPILE_TEST flag to kirkwood driver to facilitate
maintenance.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index f114dd6..1b74f4e 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -208,7 +208,7 @@
 
 config KIRKWOOD_THERMAL
 	tristate "Temperature sensor on Marvell Kirkwood SoCs"
-	depends on MACH_KIRKWOOD
+	depends on MACH_KIRKWOOD || COMPILE_TEST
 	depends on OF
 	help
 	  Support for the Kirkwood thermal sensor driver into the Linux thermal