The existing dhcpv4 initialization code places all initialization in
the per iface dhcpv4_start() code. The net_udp_register() setup needs
to happen once for the dhcpv4 instance rather than once per iface.
Subsequent patches in this series also need a place to perform one
time initialization, independent of iface.
Factor the one time setup code out of the existing net_dhcpv4_start()
into a dhcpv4_init() function. Rather than use SYS_INIT() to run
dhcpv_init() we hook directly into net_init().
The prototype of dhcpv4_init() is shared within the net subsystem with
a new private header file deliberately to avoid exposing the function
via the public API in include/net/dhcpv4.h
Change-Id: I3502a53cc3bfe4db4e4cd22c02ae133c266fdf10
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@arm.com>
Marcus Shawcroft