submodule(CoupledL2): bump CoupledL2 (#5643)

This pr includes:
- OpenXiangShan/CoupledL2#474
- OpenXiangShan/CoupledL2#475
- OpenXiangShan/CoupledL2#476

Besides, from this pr onwards, master branch must use the kunminghu-v2
branch of CoupledL2.

---------

Co-authored-by: zhanglinjuan <zhanglinjuan16@mails.ucas.ac.cn>

Author: Kumonda221-CrO3

.github/workflows/emu.yml

@@ -584,7 +584,7 @@ jobs:
       - name: check yunsuan
         run: cd yunsuan && git fetch --all && git merge-base --is-ancestor `git rev-parse HEAD` origin/master
       - name: check coupledL2
-        run: cd coupledL2 && git fetch --all && git merge-base --is-ancestor `git rev-parse HEAD` origin/master
+        run: cd coupledL2 && git fetch --all && git merge-base --is-ancestor `git rev-parse HEAD` origin/kunminghu-v2
       - name: check openLLC
         run: cd openLLC && git fetch --all && git merge-base --is-ancestor `git rev-parse HEAD` origin/master
       - name: check ChiselAIA