Currently when booting dhcp_run() may be executed multiple times:
once in eth_bootdev_hunt() and once in the network booting bootmeth.

We need to call eth_bootdev_hunt() when setting up the EFI sub-system to
supply the simple network protocol. We don't need an IP address set up.

We can reduce the bootime by not executing dhcp_run() in
eth_bootdev_hunt().

Furthermore eth_bootdev_hunt() with autostart=yes leads on the legacy
network stack leads to downloading a file via TFTP and to booting the
downloaded file.

Instead of running dchp_run() just check that there is a network device
in eth_bootdev_hunt().

Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>