platform/chrome: cros_ec_typec: Make configure_mux static

Since cros_typec_configure_mux() is only used in cros-ec-typec,
it should be marked static.

Fixes: 7e7def15 ("platform/chrome: cros_ec_typec: Add USB mux control")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

drivers/platform/chrome/cros_ec_typec.c

@@ -428,7 +428,7 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
 	return typec_mux_set(port->mux, &port->state);
 }
 
-int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
+static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
 				uint8_t mux_flags,
 				struct ec_response_usb_pd_control_v2 *pd_ctrl)
 {