python3-matplotlib: Use lld for linking when using clang

build uses LTO and for some reason it does not work well when using
clang-11

Fixes

| /mnt/b/yoe/master/build/tmp/work/armv7vet2hf-neon-yoe-linux-musleabi/python3-matplotlib/3.3.0-r0/recipe-sysroot-nat
ive/usr/bin/arm-yoe-linux-musleabi/arm-yoe-linux-musleabi-ld.gold: error: /mnt/b/yoe/master/build/tmp/work/armv7vet2h
f-neon-yoe-linux-musleabi/python3-matplotlib/3.3.0-r0/build/temp.linux-x86_64-3.8/extern/agg24-svn/src/agg_bezier_arc
.o: not an object or archive

Signed-off-by: Khem Raj <[email protected]>
Acked-by: Trevor Gamblin <[email protected]>

Author: kraj

meta-python/recipes-devtools/python/python3-matplotlib_3.3.0.bb

@@ -23,6 +23,9 @@ SRC_URI[sha256sum] = "24e8db94948019d531ce0bcd637ac24b1c8f6744ac86d2aa0eb6dbaeb1
 
 inherit pypi setuptools3 pkgconfig
 
+# LTO with clang needs lld
+LDFLAGS_append_toolchain-clang = " -fuse-ld=lld"
+
 RDEPENDS_${PN} = "\
     freetype \
     libpng \