cleanup: correct max port count on test
cleanup: correct max port count on test

Looking at code, we only test one port, so make the test
defines match the test code

BRANCH=none
BUG=none
TEST=all tests pass

Change-Id: I0b793425e20678173f3ec52fdcff4567f0b8ccb4
Signed-off-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2131047
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>

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