it8728f: Add ITE IT8728F superio early serial support.

This is the first of a series of patches to provide support
for a new mainboard, Gigabyte GA-B75M-D3V.

This patch provides early serial for the superio and has been
tested on this mainboard.  The code is based on IT8718F superio.

Change-Id: I5636199b49314166ed3b81e60b41131964dd44ff
Signed-off-by: Damien Zammit <>
Reviewed-by: Alexandru Gagniuc <>
Tested-by: build bot (Jenkins)
6 files changed