feat: implement privileged mode support

generated-ooo/PrivilegeControl.sv

@@ -0,0 +1,19 @@
+// Generated by CIRCT firtool-1.139.0
+module PrivilegeControl(
+  input        clock,
+               reset,
+  input  [1:0] io_nextPriv,
+  input        io_setPriv,
+  output [1:0] io_priv
+);
+
+  reg [1:0] privReg;
+  always @(posedge clock) begin
+    if (reset)
+      privReg <= 2'h3;
+    else if (io_setPriv)
+      privReg <= io_nextPriv;
+  end // always @(posedge)
+  assign io_priv = privReg;
+endmodule
+