clock: add APIs to access servo and servo_state

Make servo and it's current state available outside clock.c

Signed-off-by: Vedang Patel <vedang.patel@intel.com>

clock.c

@@ -1835,3 +1835,13 @@ double clock_rate_ratio(struct clock *c)
 	}
 	return servo_rate_ratio(c->servo);
 }
+
+struct servo *clock_servo(struct clock *c)
+{
+	return c->servo;
+}
+
+enum servo_state clock_servo_state(struct clock *c)
+{
+	return c->servo_state;
+}

clock.h

@@ -253,6 +253,20 @@ void clock_set_sde(struct clock *c, int sde);
  */
 int clock_poll(struct clock *c);
 
+/**
+ * Obtain the servo struct.
+ * @param c The clock instance.
+ * @return  A pointer to the clock's servo.
+ */
+struct servo *clock_servo(struct clock *c);
+
+/**
+ * Obtain the current state of clock's servo.
+ * @param c The clock instance.
+ * @return  The current state of the clock's servo.
+ */
+enum servo_state clock_servo_state(struct clock *c);
+
 /**
  * Obtain the slave-only flag from a clock's default data set.
  * @param c  The clock instance.