src/meta-openembedded: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