[CSR] Clarify PMP config assignment

Functionally pmp_mseccfg and pmp_mseccfg_q are the same when PMP is
enabled. However, the RTL is a bit more clear if both the MML and RLB
register are referenced through the pmp_mseccfg_q register name.

I thought of this clarification while analysing a question posed by
Shutong Jin during the HACK@CHES'25 event.

Author: marnovandermaas

rtl/ibex_cs_registers.sv

@@ -1183,7 +1183,7 @@ module ibex_cs_registers import ibex_pkg::*; #(
       // When MSECCFG.MML is set cannot add new regions allowing M mode execution unless MSECCFG.RLB
       // is set
       assign pmp_cfg_wr_suppress[i] = pmp_mseccfg_q.mml                   &
-                                      ~pmp_mseccfg.rlb                    &
+                                      ~pmp_mseccfg_q.rlb                  &
                                       is_mml_m_exec_cfg(pmp_cfg_wdata[i]);
 
       // --------------------------