Introduce helpers.c.

Move some suitable functions there, add it to the Makefile, but leave the
declarations in flash.h for now.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

git-svn-id: svn://flashrom.org/flashrom/trunk@1819 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Add support for Atmel AT49LH004.

Also, slightly refine the definition of AT49LH002.
TODO: unlocking is mandatory because the chips are write-protected
by default.
Refactor unlocking of many chips with locking at register space address +2.

This includes PMC Pm49*, SST 49LF00*, ST M50* and Winbond W39* family.
The erase and write test status bits of all affected chips have been reset.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
fixup! Add support for Atmel AT49LH004.
squash! Add support for Atmel AT49LH004.

and AT49LH00B4