Fix handling of write protection at register space address +2.

Since r1833 we added the offset of the virtual register in several
functions, which produced segfaults. This patch renames a few
parameters and reorganizes/fixes various parts of the
changelock_regspace2_block() function - hence the rather big diff.

Thanks to Roman Lebedev for reporting this issue and testing numerous
revisions of this patch.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1859 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Add support for the MSTAR I2C ISP protocol.

Basically, among other chips, MSTAR manufactures SoCs that equip TV sets
and computer screens, and it seems that all of their products use the
same in-system programming protocol. Basically, they use the DDC channel
of VGA or DVI connectors, which is actually an I2C bus, to encapsulate
SPI frames (the flash chip is connected to the SoC through an SPI bus).

I wrote this patch since the screen I bought had a software bug, and the
manufacturer only released a new firmware binary, but no tool or
instructions on flashing it.

More details can be found here:
http://boeglin.org/blog/index.php?entry=Flashing-a-BenQ-Z-series-for-free(dom)

I only read code from Linux kernel archives published by Acer to figure
out the protocol (for a touchscreen controller and an NFC chip, both by
MSTAR, that share the same ISP protocol), so I don't think there are
any legal problems with it.

Compilation is currently disabled by default in the Makefile.
If in doubt, additional Makefile bugs were added by Stefan.

Signed-off-by: Alexandre Boeglin <alex@boeglin.org>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1860 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1