libminc-related updates

- add files needed for acpi, ahci, fbd, vfs to libminc
- remove "-lc" from their respective makefiles
- remove setenv from libminc (requires initialization)

drivers/acpi/Makefile

@@ -134,7 +134,7 @@ ACPICA_SRCS= \
 SRCS+=${ACPICA_SRCS} 
 
 DPADD+=	${LIBSYS}
-LDADD+=	-lsys -lc
+LDADD+=	-lsys
 
 CPPFLAGS += -I${.CURDIR}/include
 CFLAGS += -DACPI_LIBRARY

drivers/ahci/Makefile

@@ -5,8 +5,6 @@ SRCS=	ahci.c
 DPADD+=	${LIBBLOCKDRIVER} ${LIBSYS} ${LIBTIMERS} ${LIBMTHREAD}
 LDADD+=	-lblockdriver -lsys -ltimers -lmthread
 
-LDADD+=	-lc
-
 MAN=
 
 BINDIR?= /sbin

drivers/fbd/Makefile

@@ -6,7 +6,7 @@ PROG=	fbd
 SRCS=	fbd.c rule.c action.c
 
 DPADD+=	${LIBBLOCKDRIVER} ${LIBSYS}
-LDADD+=	-lblockdriver -lsys -lc
+LDADD+=	-lblockdriver -lsys
 CPPFLAGS+=	-DDEBUG=0
 
 # The FBD driver requires NetBSD libc.