ifwitool: Do not calculate checksum for subpart_dir

1. The checksum method that was documented is not correct. So, no use
filling in a value based on wrong calculations. This can be added back
once updated information is available.
2. Checksum does not seem to affect the booting up of SoC. So, fill in 0
for now.

Change-Id: I0e49ac8e0e04abb6d7c9be70323612bdef309975
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15145
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed