bs: add missing codesigner command line argument
bs: add missing codesigner command line argument

The recent change of the code signer is not backwards compatible, a
new command line parameter must be added.

BRANCH=cr50
BUG=none
TEST=verified that

    H1_DEVIDS='xxxx yyyyy' ./util/signer/bs

  succeeds again.

Change-Id: I9a8e03c20aa4b7b689b1f5e4a1f786cf5857483f
Signed-off-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/527317
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec