Use HOST_QEMU_OPTS instead of patching Buildroot

run

@@ -19,15 +19,21 @@ case "$arch" in
     defconfig=qemu_arm_versatile_defconfig
     ;;
 esac
-for p in ../buildroot_patches/*.patch; do
-    patch -N -r - -p 1 <"../buildroot_patches/${p}" || :
+for p in "$(find '../buildroot_patches/' -maxdepth 1 -name '*.patch' -print)"; do
+    patch -N -r - -p 1 <"$p" || :
 done
 make BR2_EXTERNAL="$(pwd)/../kernel_module" "$defconfig"
 # TODO Can't get rid of this for now.
 # http://stackoverflow.com/questions/44078245/is-it-possible-to-use-config-fragments-with-buildroots-config
 cat ../buildroot_config_fragment >> .config
-# TODO there is no make host_qemu-rebuild ?
-rm -f output/build/host-qemu-2.7.0/.stamp_built
-env -u LD_LIBRARY_PATH make BR2_JLEVEL="$(($(nproc) - 2))" kernel_module-rebuild all
+env \
+  -u LD_LIBRARY_PATH \
+  make \
+  BR2_JLEVEL="$(($(nproc) - 2))" \
+  HOST_QEMU_OPTS="--enable-sdl --with-sdlabi=2.0" \
+  host-qemu-rebuild \
+  kernel_module-rebuild \
+  all \
+;
 cd ..
 ./runqemu "$@"