clang-ignore: remove unneeded file

The code formatting tools have been updated so that this clang-ignore
is no longer necessary.  Meson will use 'git ls-files' by default and
the org-wide tools do as well now.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie337eb60d3f87ffab8dcbf4ef33990c432bf82ce
diff --git a/.clang-ignore b/.clang-ignore
deleted file mode 100644
index 36f17f2..0000000
--- a/.clang-ignore
+++ /dev/null
@@ -1 +0,0 @@
-./subprojects