uboot: Apply patches outside container

When running inside a rootless Podman container on a SELinux-enabled
host, the `patch` command fails because it cannot copy SELinux labels
from the original file to the patched file.  This only happens patching
files that are located in a bind mount.

podman-build.sh

@@ -20,6 +20,8 @@ cid=$(podman run \
     python -c 'from signal import *;signal(SIGTERM, lambda x, y: None);pause()'
 )
 
+./patch-uboot.sh
+
 podman exec -it ${cid} ./build-all.sh "${target}"
 
 podman stop ${cid}