[coreboot] w83627 uart port is not workable with coreboot in linux

[cheng yichen]

Hi all

My platform is braswell SOC with W83627dhg superIO. In post stage I can get
debug message over w83627 uart1(3f8/irq4). but after boot to linux, uart
port is not woarkable. I test the function by minicom but I can't receive
and send data. I can get uart information by dmesg command.
How to initial it in corebooot?
Thank you