[dv/kmac] Remove cycle accurate scb [Part 3]
[dv/kmac] Remove cycle accurate scb [Part 3]

This PR removes the stalling variables that were related to the cycle
accurate scb from Part2 clean up.

Signed-off-by: Cindy Chen <399ad771a111eac8923348b1e2af093034e5d4f1@opentitan.org>

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