thermal/drivers/core: Use governor table to initialize

Now that the governor table is in place and the macro allows to browse the
table, declare the governor so the entry is added in the governor table
in the init section.

The [un]register_thermal_governors function does no longer need to use the
exported [un]register thermal governor's specific function which in turn
call the [un]register_thermal_governor. The governors are fully
self-encapsulated.

The cyclic dependency is no longer needed, remove it.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
diff --git a/drivers/thermal/gov_bang_bang.c b/drivers/thermal/gov_bang_bang.c
index 632fb92..e0575d2 100644
--- a/drivers/thermal/gov_bang_bang.c
+++ b/drivers/thermal/gov_bang_bang.c
@@ -116,13 +116,4 @@ static struct thermal_governor thermal_gov_bang_bang = {
 	.name		= "bang_bang",
 	.throttle	= bang_bang_control,
 };
-
-int thermal_gov_bang_bang_register(void)
-{
-	return thermal_register_governor(&thermal_gov_bang_bang);
-}
-
-void thermal_gov_bang_bang_unregister(void)
-{
-	thermal_unregister_governor(&thermal_gov_bang_bang);
-}
+THERMAL_GOVERNOR_DECLARE(thermal_gov_bang_bang);