spike: Bump version from d1efcdf to 20a2b6d

cmuellner · cmuellner · commit c059d5cca3ba · 2024-04-26T10:01:36.000+02:00
```
               ========= Summary of gcc testsuite =========
                            | # of unexpected case / # of unique unexpected case
                            |          gcc |          g++ |     gfortran |
     rv64gc/  lp64d/ medlow |    0 /     0 |    0 /     0 |      - |
  rv32imafc/ ilp32f/ medlow |    0 /     0 |    0 /     0 |      - |
```

Signed-off-by: Christoph Müllner &lt;christoph.muellner@vrull.eu&gt;
diff --git a/spike b/spike
@@ -1 +1 @@
-Subproject commit d1efcdffffee57bab0fdbd2b377c6132b37556fd
+Subproject commit 20a2b6d05a562236a32ca3ce1642a2bdbbd907a0
