editorConfig: use tabs instead of spaces (indent stays 4)

The vast majority of PCSX2 files use tabs for indentations, and all new
commits also use tabs for indents and not spaces. Therefore, having space
.editorConfig makes it extremely hard to work on PCSX2 files with editors
which support this config file.

There were some concerns that github will make things harder for us
with tabs at .editorConfig, and if that indeed becomes an issue then
we'll have to address it somehow. For now, let's hope it won't.

Also, commented out the line which automatically removes trailing
spaces, since it affects the entire file and therefore makes changes
which the committer did not intend to make at places unrelated to the
commit.

.editorconfig

@@ -4,9 +4,9 @@ root = true
 # TODO: Add one for resource script file and other Linux specific files ?
 
 [*.{cpp,h}]
-indent_style = space
+indent_style = tab
 indent_size = 4
-trim_trailing_whitespace = true
+#trim_trailing_whitespace = true
 
 [*.md]
 trim_trailing_whitespace = false