[dv/otp_ctrl] Force mubi value for hw cfg read lock

[cindychip]

Description

In current testbench, the hw_cfg partition cannot be read locked.
And the current otp_ctrl_base_vseq function only force the mubi bits to invalid values (non mubi true or false) if the mubi value is locked. (Because any invalid values are treated as mubi false, then scb does not need to probe and know the force mubi value)

So, we cannot force the hw cfg partition to invalid mubi values.

This is marked as M3 because in chip level, we can never lock the hw_cfg partition's read access.

[msfschaffner]

This should be ok since the read access for that partition should not be lockable.