dhclient: Remove dhcp bbappend

With commit https://cgit.openembedded.org/openembedded-core/commit/meta/recipes-connectivity/dhcp?id=7e3357892f204788162747e907d68f857118cf42
dhcp was removed inf favor of dhcpd. Resemble this removal.

Currently, we do not have a replacement configured.

recipes-connectivity/dhcp/dhcp/dhclient.conf

-# Configuration file for /sbin/dhclient, which is included in Debian's
-#	dhcp3-client package.
-#
-# This is a sample configuration file for dhclient. See dhclient.conf's
-#	man page for more information about the syntax of this file
-#	and a more comprehensive list of the parameters understood by
-#	dhclient.
-#
-# Normally, if the DHCP server provides reasonable information and does
-#	not leave anything out (like the domain name, for example), then
-#	few changes must be made to this file, if any.
-#
-
-send host-name = gethostname();
-#send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
-#send dhcp-lease-time 3600;
-#supersede domain-name "fugue.com home.vix.com";
-#prepend domain-name-servers 127.0.0.1;
-request subnet-mask, broadcast-address, time-offset, routers,
-	domain-name, domain-name-servers,
-	netbios-name-servers, netbios-scope;
-#require subnet-mask, domain-name-servers;
-#timeout 60;
-#retry 60;
-#reboot 10;
-#select-timeout 5;
-#initial-interval 2;
-#script "/etc/dhcp3/dhclient-script";
-#media "-link0 -link1 -link2", "link0 link1";
-#reject 192.33.137.209;
-
-#alias {
-#  interface "eth0";
-#  fixed-address 192.5.5.213;
-#  option subnet-mask 255.255.255.255;
-#}
-
-#lease {
-#  interface "eth0";
-#  fixed-address 192.33.137.200;
-#  medium "link0 link1";
-#  option host-name "andare.swiftmedia.com";
-#  option subnet-mask 255.255.255.0;
-#  option broadcast-address 192.33.137.255;
-#  option routers 192.33.137.250;
-#  option domain-name-servers 127.0.0.1;
-#  renew 2 2000/1/12 00:00:01;
-#  rebind 2 2000/1/12 00:00:01;
-#  expire 2 2000/1/12 00:00:01;
-#}

recipes-connectivity/dhcp/dhcp_%.bbappend

-FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"