Revert "serial: i.MX: evaluate linux,stdout-path property"

This reverts commit f7d2c0bb, as it
causes build errors when the driver is built as a module.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>