Add external flasher support

- Read/write accesses through function pointers
- Command line parameter for internal/external flasher
- Board and chipset setup moved to internal init function
- Shutdown stuff moved to internal shutdown function

As a side benefit, this will allow us to undo chipset write enable
during shutdown.

Tested by Uwe on real hardware.

Corresponding to flashrom svn r476.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/Makefile b/Makefile
index 8c42343..ecaef6c 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,7 @@
 	w49f002u.o 82802ab.o pm49fl00x.o sst49lf040.o en29f002a.o \
 	sst49lfxxxc.o sst_fwhub.o layout.o cbtable.o flashchips.o physmap.o \
 	flashrom.o w39v080fa.o sharplhf00l04.o w29ee011.o spi.o it87spi.o \
-	ichspi.o w39v040c.o sb600spi.o wbsio_spi.o m29f002.o
+	ichspi.o w39v040c.o sb600spi.o wbsio_spi.o m29f002.o internal.o
 
 all: pciutils dep $(PROGRAM)