[openwrt/openwrt] toolchain: Include ./include/fortify for external musl toolchain

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/629199f6c8e0dc36484dd17e971f8c1c88b705b1

commit 629199f6c8e0dc36484dd17e971f8c1c88b705b1
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Mon Sep 12 00:31:43 2022 +0200

    toolchain: Include ./include/fortify for external musl toolchain
    
    When building with an external toolcahin with musl also include
    ./include/fortify by default. This is also done when we build with the
    internal toolchain using musl libc.
    
    Without this extra include the fortify source feature is not working
    when using an external musl toolchain. All binaries were compiled
    without fortify source when an external musl toolchain was used. All
    binaries release done by the OpenWrt project use the internal toolcahin
    where fortify source is working.
    
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
    (cherry picked from commit 3053045093a5c89dad970b7db3ed9f2a5be993f6)
    Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>
---
 toolchain/Config.in | 1 +
 1 file changed, 1 insertion(+)

diff --git a/toolchain/Config.in b/toolchain/Config.in
index 6dda9af92d..c30928854b 100644
--- a/toolchain/Config.in
+++ b/toolchain/Config.in
@@ -135,6 +135,7 @@ menuconfig EXTERNAL_TOOLCHAIN
 		string
 		prompt "Toolchain include path"  if DEVEL
 		depends on EXTERNAL_TOOLCHAIN && !NATIVE_TOOLCHAIN
+		default "./usr/include ./include/fortify ./include" if EXTERNAL_TOOLCHAIN_LIBC_USE_MUSL
 		default "./usr/include ./include"
 		help
 		  Specify additional directories searched for header files (override