[chip dv] Fix X detection logic on IOs
[chip dv] Fix X detection logic on IOs

Switched to a more clear, concise always block with a generate
block. It correctly flags Xs on IOs sooner.

Signed-off-by: Srikrishna Iyer <2803d640feace36379942447842f26c7747b4dc3@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan