net: dhcp: clear option state when selecting
net: dhcp: clear option state when selecting

When a connection is lost the client will first attempt to renew, and
then to rebind, and finally to select.  Options like gateway may have
been provided by the original connection, but not the new connection,
resulting in an inconsistent configuration for the new network.

Remove the partial state clearing when entering INIT, and expand the
state cleared when entering SELECTING to be more comprehensive.

Signed-off-by: Peter Bigot <a4112a160b558d5427af084318038e19a95979ee@nordicsemi.no>

Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr