serial: altera: Adopt uart_console_write()

This driver does not currently use uart_console_write() and instead
provides is own LF to LFCR conversion in it's console_write() method.
We should use the library function instead.

Cmopile tested only (with ARCH=arm).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>