insts_base: ignore architecture in SFENCE_VMA

architecture doesn't change the behavior, so there is no reason to
complicate the code with it.

The code is still suboptimal because of rhs duplication, so this should
be rewritten if (when) Sail supports multiple matches like:
  User    or (Supervisor if mstatus[TVM] == 0b1) => ...
  Machine or (Supervisor if mstatus[TVM] == 0b0) => ...

(Separately mapping those four cases into two and matching on the two is
 also an option, but I'm not sure it would be clearer.)

Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>

model/riscv_insts_base.sail

@@ -714,9 +714,9 @@ function clause execute SFENCE_VMA(rs1, rs2) = {
   let asid = if rs2 != zreg then Some(X(rs2)[asidlen - 1 .. 0]) else None();
   match cur_privilege {
     User       => { handle_illegal(); RETIRE_FAIL },
-    Supervisor => match (architecture(get_mstatus_SXL(mstatus)), mstatus[TVM]) {
-                    (_, 0b1)  => { handle_illegal(); RETIRE_FAIL },
-                    (_, 0b0) => { flush_TLB(asid, addr); RETIRE_SUCCESS },
+    Supervisor => match mstatus[TVM] {
+                    0b1 => { handle_illegal(); RETIRE_FAIL },
+                    0b0 => { flush_TLB(asid, addr); RETIRE_SUCCESS },
                   },
     Machine    => { flush_TLB(asid, addr); RETIRE_SUCCESS }
   }