Most of the code has been taken from SLOF's netload.c file. Now we
can finally load an image via TFTP and execute the downloaded kernel.

Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1499863793-18627-12-git-send-email-thuth@redhat.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>