busybox config options disabled to build on GNU/kFreeBSD

referred to "debian/config/udeb" in the "busybox_1.13.3-1" Debian package


CONFIG_MONOTONIC_SYSCALL	# not strictly required				# it may be a good idea later to wire up the call to the corresponding kFreeBSD syscalls
CONFIG_DMESG			# not strictly necessary			# freebsd-utils # nice to have
CONFIG_FREERAMDISK		# ok
CONFIG_PIVOT_ROOT		# perhaps not necessary				# used at the end of the execution of the initrd on a normal Linux boot process
CONFIG_FEATURE_MOUNT_LOOP	# ok
CONFIG_IP			# needed sooner or later			# freebsd-utils
CONFIG_ROUTE			# needed sooner or later			# freebsd-utils
CONFIG_APP_UDHCPC		# needed sooner or later			# freebsd-utils
CONFIG_FEATURE_UDHCPC_ARPING	# needed sooner or later			# freebsd-utils
CONFIG_KLOGD			# ok as a first step, maybe needed later