thermal: exynos: allow compile test

Adding COMPILE_TEST flag to exynos driver to facilitate
maintenance.

Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/Kconfig

@@ -353,7 +353,7 @@ source "drivers/thermal/ti-soc-thermal/Kconfig"
 endmenu
 
 menu "Samsung thermal drivers"
-depends on ARCH_EXYNOS
+depends on ARCH_EXYNOS || COMPILE_TEST
 source "drivers/thermal/samsung/Kconfig"
 endmenu