serial: altera_jtaguart: Adpot uart_console_write()

Follow commit 2970b7f5ea3c ("serial: altera: Adopt
uart_console_write()") and don't open code the LF to LFCR conversion in
altera_jtaguart either. Use uart_console_write() instead.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>