consolodate Makefiles

The tree contained many operating system specific Makefiles which were
being included in other Makefiles. This commit removes those and adds
the code to the makefiles which included them using make's conditional
processing.

X-Gentoo-Bug: 387441
X-Gentoo-Bug-URL: http://bugs.gentoo.org/show_bug.cgi?id=387441

conf.d/Makefile

@@ -6,7 +6,16 @@ CLEANFILES+=	network staticroute
 
 MK=	../mk
 include ${MK}/os.mk
-include Makefile.${OS}
+
+ifeq ($(OS),FreeBSD)
+CONF+=	ipfw moused powerd rarpd savecore syscons
+else ifeq ($(OS),Linux)
+CONF+=	consolefont dmesg hwclock keymaps killprocs modules
+SOS=	Linux
+else ifeq ($(OS),NetBSD)
+CONF+=	moused rarpd savecore
+endif
+
 include ${MK}/scripts.mk
 
 SOS?=	BSD