x86: Set serial port IRQ for SMSC LPC47M

For starting a Linux console on the superio serial port under
interrupt mode, the IRQ number must be configured.

Signed-off-by: Jian Luo <jian.luo4@boschrexroth.de>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
5 files changed