Add AfterCaseLabel to .clang-format

Update the .clang-format file to include AfterCaseLabel.  This change is
driven by the move to clang-10.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I9437db42ff54c5c987d10d18e4f56d155232f82c
diff --git a/.clang-format b/.clang-format
index 2806478..44865d0 100644
--- a/.clang-format
+++ b/.clang-format
@@ -20,6 +20,7 @@
 BinPackArguments: true
 BinPackParameters: true
 BraceWrapping:
+  AfterCaseLabel:  true
   AfterClass:      true
   AfterControlStatement: true
   AfterEnum:       true