linux: drop unused 5.15 version

* 6.1 version was used by default since mickledore:
  https://github.com/agherzan/meta-raspberrypi/commit/12a1187b01644cb444106f7c8f498fbf519be276
  and kirkstone for rpi5 MACHINEs since:
  https://github.com/agherzan/meta-raspberrypi/commit/9dc6673d41044f1174551120ce63501421dbcd85

* scarthgap uses 6.6 by default since:
  https://github.com/agherzan/meta-raspberrypi/commit/1cf3dd5e5ef86c5196c8544853857ab1561c748b

* nobody is probably using 5.15 with newer release and there are issues with "iw reg" since
  wireless-regdb upgrade in oe-core as well as shown in:
  https://github.com/agherzan/meta-raspberrypi/pull/1317
  so better to drop it from master/scarthgap together with
  rpi.scc used only for 5.15 and 0001-gcc-plugins-Reorganize-gimple-includes-for-GCC-13.patch
  used only by rpi.scc

Signed-off-by: Martin Jansa <martin.jansa@gmail.com>

recipes-kernel/linux/files/0001-gcc-plugins-Reorganize-gimple-includes-for-GCC-13.patch

@@ -1,50 +0,0 @@
-From 32f53700aeef2f5c7797ddda66348fc0b29e1047 Mon Sep 17 00:00:00 2001
-From: Kees Cook <keescook@chromium.org>
-Date: Wed, 18 Jan 2023 12:21:35 -0800
-Subject: [PATCH] gcc-plugins: Reorganize gimple includes for GCC 13
-
-The gimple-iterator.h header must be included before gimple-fold.h
-starting with GCC 13. Reorganize gimple headers to work for all GCC
-versions.
-
-Reported-by: Palmer Dabbelt <palmer@rivosinc.com>
-Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
-Link: https://lore.kernel.org/all/20230113173033.4380-1-palmer@rivosinc.com/
-Cc: linux-hardening@vger.kernel.org
-Signed-off-by: Kees Cook <keescook@chromium.org>
----
-Upstream-Status: Pending
-
- scripts/gcc-plugins/gcc-common.h | 4 ++--
- 1 file changed, 2 insertions(+), 2 deletions(-)
-
-diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h
-index 0c087614fc3e..27770c31214c 100644
---- a/scripts/gcc-plugins/gcc-common.h
-+++ b/scripts/gcc-plugins/gcc-common.h
-@@ -77,8 +77,10 @@
- #include "varasm.h"
- #include "stor-layout.h"
- #include "internal-fn.h"
-+#include "gimple.h"
- #include "gimple-expr.h"
- #include "gimple-fold.h"
-+#include "gimple-iterator.h"
- #include "context.h"
- #include "tree-ssa-alias.h"
- #include "tree-ssa.h"
-@@ -91,11 +93,9 @@
- #include "tree-eh.h"
- #include "stmt.h"
- #include "gimplify.h"
--#include "gimple.h"
- #include "tree-ssa-operands.h"
- #include "tree-phinodes.h"
- #include "tree-cfg.h"
--#include "gimple-iterator.h"
- #include "gimple-ssa.h"
- #include "ssa-iterators.h"
- 
--- 
-2.39.1
-

recipes-kernel/linux/files/rpi.scc

@@ -1 +0,0 @@
-patch 0001-gcc-plugins-Reorganize-gimple-includes-for-GCC-13.patch