MLPE state at reset is 0 (riscv#1592)

src/machine.adoc

@@ -2519,7 +2519,9 @@ the platform mandates a different reset value for some PMP registers’ A
 and L fields. If the hypervisor extension is implemented, the
 `hgatp`.MODE and `vsatp`.MODE fields are reset to 0. If the Smrnmi
 extension is implemented, the `mnstatus`.NMIE field is reset to 0. No
- *WARL* field contains an illegal value. All other hart state is UNSPECIFIED.
+ *WARL* field contains an illegal value. If the Zicfilp extension is
+implemented, the `mseccfg`.MLPE field is reset to 0. All other hart
+state is UNSPECIFIED.
 
 The `mcause` values after reset have implementation-specific
 interpretation, but the value 0 should be returned on implementations