rust-sdl2: Force unix line-endings for patches (#1080)

This fixes an issue where the *.patch files get windows line endings
when checked out on windows, which breaks the bundled build when
building from git directly.

Author: waych

.gitattributes

@@ -0,0 +1 @@
+*.patch eol=lf

changelog.md

@@ -5,6 +5,7 @@ when upgrading from a version of rust-sdl2 to another.
 
  * Add patch to fix metal detection (https://bugzilla.libsdl.org/show_bug.cgi?id=4988)
  * Changed signature of TimerSubsystem::ticks to accept `&self`.
+[PR #1080](https://github.com/Rust-SDL2/rust-sdl2/pull/1080): Fix line endings of patches to lf so patching of sources works on Windows.
 
 ### v0.34.4