Add AfterCaseLabel for clang-format-10

Clang-format-10 has a different default for case labels; add this to
keep the current format.

Change-Id: I7ffd6c6fbe72c7cc365690c81b7f2e1f3d31b338
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
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