IOEX: Fix clobbering of initial flag values
IOEX: Fix clobbering of initial flag values

Do not clobber initial io-expander flag values set in
board files.

BUG=b:203907721
BRANCH=none
TEST=ServoV4p1 flags are not clobbered and IO-Expanders are working

Signed-off-by: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.org>
Change-Id: If5d899de5071d8a8e7594de10e2efd4dfb83e838
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3239014
Tested-by: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.com>
Reviewed-by: caveh jalali <08e24a66aefda7a55ca7d73f8903e0fb16eec763@chromium.org>
Reviewed-by: Brian J. Nemec <4bb9322d2721abaa797f20e8e3863e6a19240e0a@chromium.org>
Commit-Queue: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.com>

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