[dv] Add rv_dm UNR generated exclusions.

[moidx]

UNR was generated from rv_dm block level regression coverage results.

This is part of https://github.com/lowRISC/opentitan/issues/22472.

Before:

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	GROUP
83.70 %	96.18 %	85.20 %	89.91 %	73.75 %	88.33 %	98.42 %	54.13 %

After:

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	GROUP
84.89 %	96.32 %	86.85 %	92.10 %	73.75 %	90.44 %	98.42 %	56.31 %