MIPS: AR7: Ensure that serial ports are properly set up

MIPS: AR7: Ensure that serial ports are properly set up

Without UPF_FIXED_TYPE, the data from the PORT_AR7 uart_config entry is
never copied, resulting in a dead port.

Fixes: 154615d55459 ("MIPS: AR7: Use correct UART port type")
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
[jonas.gorski: add Fixes tag]
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Cc: linux-mips@linux-mips.org
Cc: linux-serial@vger.kernel.org
Cc: <stable@vger.kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/17543/
Signed-off-by: James Hogan <jhogan@kernel.org>