Remove some unused TFTP and DBUS support

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
    - tethering started and dnsmasq does DHCPv4 and DNS as usual
Bug: 38364896
Change-Id: Icedd01389c3c971f121d4905dad11f26bd49bbd9
11 files changed