linux (Generic): drop obsolete libelf detection patch

Signed-off-by: Matthias Reichl <hias@horus.com>

packages/linux/patches/default/linux-900-fix-libelf-detection.patch

@@ -1,16 +0,0 @@
-diff --git a/Makefile b/Makefile
-index c9132594860b..9551c8bc5e91 100644
---- a/Makefile
-+++ b/Makefile
-@@ -933,7 +933,7 @@ export mod_sign_cmd
- 
- ifdef CONFIG_STACK_VALIDATION
-   has_libelf := $(call try-run,\
--		echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
-+		echo "int main() {}" | $(HOSTCC) $(HOSTCFLAGS) -xc -o /dev/null $(HOSTLDFLAGS) -lelf -,1,0)
-   ifeq ($(has_libelf),1)
-     objtool_target := tools/objtool FORCE
-   else
--- 
-2.11.0
-