g: upgrade_fw: check board id if CR50_RELAXED isn't defined
g: upgrade_fw: check board id if CR50_RELAXED isn't defined

CL:1529834 mistakenly changed an ifndef to a ifdef.

If CR50_RELAXED is defined, contents_allowed should always return True.
In a normal image contents_allowed should check the board id before an
update. This  change changes the ifdef back to ifndef which is what it
should be.

BUG=none
BRANCH=cr50
TEST=create dbg image and try to flash an image with a mismatched board
id. Make sure it runs ok. Build a non dbg image and make sure mismatched
board id images are rejected.

Change-Id: I1dcef5a6af4edbb431fe894ca37df5dc4e1b852e
Signed-off-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1561972
Reviewed-by: Abe Levkoy <2e1ad7039298f93262cf06bbb457275fb3e2ecb5@chromium.org>
Reviewed-by: Namyoon Woo <e8732cefb861f07768f47df788a8e8eb75efc09a@chromium.org>

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