net/dhcpcd-devel: disable udev support in CONFIGURE_ARGS, given that
FreeBSD has the function udev_device_new_from_subsystem_sysname if the
module libudev-devd is installed, but it is not implemented.

PR: 247144
Reported by: Greg V <greg@unrelenting.technology>
Reviewed by: Roy Marples <roy@marples.name>