We don't need dev_err() message because when something goes wrong,
platform_get_irq() has print an error message itself, so we should
remove duplicate dev_err().

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>