dhcp: 4.3.5 -> 4.3.6

dhcp: 4.3.5 -> 4.3.6

1. Rebase patches to 4.3.6
- define-macro-_PATH_DHCPD_CONF-and-_PATH_DHCLIENT_CON.patch -> 0001
- dhcp-3.0.3-dhclient-dbus.patch -> 0002
- link-with-lcrypto.patch -> 0003
- fixsepbuild.patch -> 0004
- dhclient-script-drop-resolv.conf.dhclient.patch -> 0005
- 0001-site.h-enable-gentle-shutdown.patch -> 0006
- libxml2-configure-argument.patch -> 0007
- tweak-to-support-external-bind.patch -> 0008
- remove-dhclient-script-bash-dependency.patch -> 0009
- build-shared-libs.patch -> 0010
- Moved-the-call-to-isc_app_ctxstart-to-not-get-signal.patch -> 0011

2. Drop search-for-libxml2.patch
   It is overrided by libxml2-configure-argument.patch

3. Rework dhclient-script-drop-resolv.conf.dhclient.patch and
Drop replace-ifconfig-route.patch.
vim client/scripts/linux
...
Script refresh in 2017. The aliasing code was too convoluted and needs
to go away. Migrated DHCPv4 script to ip command from iproute2 suite.
This is based on Debian script with some tweaks. ifconfig is no longer
used. Everything is done using ip tool from ip-route2.
...

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>