BMI INT2 can be input or output.
It is not used currently, but configure it properly nevertheless.
BUG=none
BRANCH=none
TEST=On cave, (int2 is output), ensure FIFO headers are free of
interrupt information.
Change-Id: I9c058689a8676593aad542e33601cc11da105838
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/394066