fix warning "control reaches end of non-void function"

Add a return 0 analogous to uart_mxc_port[0-2]_exit.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Holger Schurig <hs4233@mail.mn-solutions.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Martin Fuzzey <mfuzzey@gmail.com>
1 file changed