add Packet hub driver for Topcliff Platform controller hub

add Packet hub driver for Topcliff Platform controller hub

Packet hub driver of Topcliff PCH

Topcliff PCH is the platform controller hub that is going to be used in
Intel's upcoming general embedded platform. All IO peripherals in
Topcliff PCH are actually devices sitting on AMBA bus. Packet hub is
a special converter device in Topcliff PCH that translate AMBA transactions
to PCI Express transactions and vice versa. Thus packet hub helps present
all IO peripherals in Topcliff PCH as PCIE devices to IA system.
Topcliff PCH has MAC address and Option ROM data.
These data are in SROM which is connected to PCIE bus.
Packet hub driver of Topcliff PCH can access MAC address and Option ROM data in
SROM via sysfs interface.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>