.gitignore: sort normal pattern rules alphabetically

commit 1377dd3e29878b8f5d9f5c9000975f50a428a0cd upstream.

We are having more and more ignore patterns.  Sort the list
alphabetically.  We will easily catch duplicated patterns if any.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>