In preparation to support mutiple efi net udevices. Add a device path
cache to support device paths from multiple ethernet udevices.
The device paths can be added to the cache before EFI gets initialized and
the protocols get installed.
Signed-off-by: Adriano Cordova <adriano.cordova@canonical.com>
Add an implementation of the EFI_IP4_CONFIG2_PROTOCOL. The protocol
is attached to the handle of the efi network device. This is the same
handle where snp and pxe are attached to.
Signed-off-by: Adriano Cordova <adrianox@gmail.com>