Add .editorconfig

Github uses tab width from .editorconfig when displaying code.

Change-Id: I9dcbe192ca21d7606a6ae56c747acd271562358c
diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..f6e168f
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,9 @@
+root = true
+
+[*.{c,h,cpp,hpp,txt,md,inl,py,mk,java,sh,xml}]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+indent_style = tab
+indent_size = 4
+trim_trailing_whitespace = true