Add dhcpcd 5.6.6.

	new file:   base/dhcpcd/dhcpcd-5.6.6-rundir.patch.xz
	new file:   base/dhcpcd/dhcpcd-5.6.6-slackware.patch.xz
	new file:   base/dhcpcd/dhcpcd-5.6.6-slackwareservice.patch.xz
	new file:   base/dhcpcd/dhcpcd.build