clang-format: add AfterCaseLabel option from clang-10

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Id8b3a3f8bb1e892ab1fa6b4252a24243a3eaa818
diff --git a/.clang-format b/.clang-format
index ea71ad6..692faa2 100644
--- a/.clang-format
+++ b/.clang-format
@@ -21,6 +21,7 @@
 BinPackArguments: true
 BinPackParameters: true
 BraceWrapping:
+  AfterCaseLabel:  true
   AfterClass:      true
   AfterControlStatement: true
   AfterEnum:       true