Log Message:
Import dhcpcd-5.2.2 with the following changes:
* The broadcast flag is now automatically set for interfaces that require
  it, via platform detection. Currently qeth on Linux.
* Fix a file descriptor leak on Linux getting platform info.
* Don't send a maximum DHCP message size beyond what we can handle.
* ip_ip is now randomized.
* IPTOS_LOWDELAY and IP_DF flags are no longer set.
* SSID is now correctly terminated on Linux.