clang-ignore: rename

Currently openbmc-build-scripts will accept either .clang-ignore
or .clang-format-ignore.  Meson by default looks at the
.clang-format-ignore name.  Switch to using that one for broader
compatibility.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Icea371667ab9bdd27763c557b19572f7d99cb375
diff --git a/.clang-ignore b/.clang-format-ignore
similarity index 100%
rename from .clang-ignore
rename to .clang-format-ignore