librem5: workaround atf bug on some compilers

Makefile

@@ -296,6 +296,7 @@ src/u-boot-librem5:
 	@mkdir src/u-boot-librem5
 	@wget https://source.puri.sm/Librem5/u-boot-builder/-/archive/3b1c7d957f46c87c6cdd71cd8dab7c84aca26570/u-boot-builder-3b1c7d957f46c87c6cdd71cd8dab7c84aca26570.tar.gz
 	@tar -xf u-boot-builder-3b1c7d957f46c87c6cdd71cd8dab7c84aca26570.tar.gz --strip-components 1 -C src/u-boot-librem5
+	@cd src/u-boot-librem5 && patch -p1 < ../librem5-atf-bug.patch
 
 src/u-boot-pocketpc:
 	@echo "WGET  u-boot-pocketpc"

src/librem5-atf-bug.patch

@@ -0,0 +1,18 @@
+diff --git a/build_uboot.sh b/build_uboot.sh
+index d9fb650..9a4b428 100755
+--- a/build_uboot.sh
++++ b/build_uboot.sh
+@@ -101,8 +101,13 @@ function build_atf()
+         git clone "${ATF_REPO}"
+     fi
+     cd "${ATF_DIR}"
++    git reset --hard
++    git clean -f -d
+     git checkout "${ATF_BRANCH}"
+ 
++    # Remove -Werror to workaround a compiler bug
++    sed -i 's/-Werror//g' Makefile
++
+     make PLAT="${ATF_PLAT}" CROSS_COMPILE="${CROSS_COMPILER}"  bl31
+     
+     cd "${CWD}"