The RTL8153-AD supports a persistent system specific MAC address.
This means a device plugged into two different systems with host side
support will show different (but persistent) MAC addresses.

This information for the system's persistent MAC address is burned in when
the system HW is built and available under \_SB.AMAC in the DSDT at runtime.

This technology is currently implemented in the Dell TB15 and WD15 Type-C
docks.  More information is available here:
http://www.dell.com/support/article/us/en/04/SLN301147Signed-off-by: Mario Limonciello <mario_limonciello@dell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>