vendor-reset: fix build on Linux 6.12

`asm/unaligned.h` has been moved to `linux/unaligned.h` since
Linux v. 6.12 [^1]. This has broken the build for `vendor-reset`
on newer versions.

I've opened a PR with the upstream project [^2], but that has been
sitting unmerged on GitHub for a while now, so I decided to add the
fix temporarily using `fetchpatch` in the NixOS module for now.
When it will (hopefully) eventually be merged, we should be able to
remove the patch and just switch to an up-to-date upstream version.

[^1]: https://github.com/torvalds/linux/commit/5f60d5f6bbc12e782fac78110b0ee62698f3b576
[^2]: https://github.com/gnif/vendor-reset/pull/86

pkgs/os-specific/linux/vendor-reset/default.nix

···
     hash = "sha256-Klu2uysbF5tH7SqVl815DwR7W+Vx6PyVDDLwoMZiqBI=";
   };
 
+  patches = [
+    # This is a temporary, vendored version of this upstream PR:
+    # https://github.com/gnif/vendor-reset/pull/86
+    # As soon as it is merged, we should be able to update this
+    # module and remove the patch.
+    ./fix-linux-6.12-build.patch
+  ];
+
   nativeBuildInputs = kernel.moduleBuildDependencies;
 
   hardeningDisable = [ "pic" ];

pkgs/os-specific/linux/vendor-reset/fix-linux-6.12-build.patch

···
+From ab1b34848097587aca1f248958358ddb1dc90917 Mon Sep 17 00:00:00 2001
+From: mfrischknecht <[e-mail]>
+Date: Sat, 23 Nov 2024 23:43:53 +0100
+Subject: [PATCH 1/2] Import `unaligned.h` from `linux`
+
+`asm/unaligned.h` has been moved to `linux/unaligned.h` since Linux v. 6.12.
+C.f. e.g. https://github.com/torvalds/linux/commit/5f60d5f6bbc12e782fac78110b0ee62698f3b576
+---
+ src/amd/amdgpu/atom.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/amd/amdgpu/atom.c b/src/amd/amdgpu/atom.c
+index 333961f..d14c849 100644
+--- a/src/amd/amdgpu/atom.c
++++ b/src/amd/amdgpu/atom.c
+@@ -29,7 +29,7 @@
+ #include <linux/slab.h>
+ #include <linux/delay.h>
+ #include <linux/version.h>
+-#include <asm/unaligned.h>
++#include <linux/unaligned.h>
+ 
+ //#include <drm/drm_util.h>
+ //#include <drm/drm_print.h>
+
+From 54ffd6a012e7567b0288bc5fcc3678b545bd5aec Mon Sep 17 00:00:00 2001
+From: mfrischknecht <[e-mail]>
+Date: Wed, 27 Nov 2024 07:09:37 +0100
+Subject: [PATCH 2/2] Make new include path conditional
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+…so the module builds for both kernels below 6.12 and above. Thanks, @VoodaGod!
+
+Co-authored-by: Jason Rensburger <[e-mail]>
+---
+ src/amd/amdgpu/atom.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/amd/amdgpu/atom.c b/src/amd/amdgpu/atom.c
+index d14c849..36d45ff 100644
+--- a/src/amd/amdgpu/atom.c
++++ b/src/amd/amdgpu/atom.c
+@@ -29,7 +29,11 @@
+ #include <linux/slab.h>
+ #include <linux/delay.h>
+ #include <linux/version.h>
++#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 12, 0)
++#include <asm/unaligned.h>
++#else
+ #include <linux/unaligned.h>
++#endif
+ 
+ //#include <drm/drm_util.h>
+ //#include <drm/drm_print.h>