arch,sim: Stop decoding the pseudo inst subfunc value.

This isn't used by anything any more. The func field is left in place
to ensure compatability, but there's no reason to decode a value
nobody is going to use.

Jira Issue: https://gem5.atlassian.net/browse/GEM5-187

Change-Id: I85fcd0e4a362551c29af6bff350d99af86050415
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23179
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/sim/pseudo_inst.hh

@@ -123,14 +123,13 @@ void togglesync(ThreadContext *tc);
  * manner using the ISA-specific getArguments functions.
  *
  * @param func M5 pseudo op major function number (see utility/m5/m5ops.h)
- * @param subfunc M5 minor function number. Mainly used for annotations.
  */
 
 template <typename ABI>
 uint64_t
-pseudoInst(ThreadContext *tc, uint8_t func, uint8_t subfunc)
+pseudoInst(ThreadContext *tc, uint8_t func)
 {
-    DPRINTF(PseudoInst, "PseudoInst::pseudoInst(%i, %i)\n", func, subfunc);
+    DPRINTF(PseudoInst, "PseudoInst::pseudoInst(%i)\n", func);
 
     switch (func) {
       case M5OP_ARM: