Bail on more errors.
General tool for installing DTS files; use with BeagleBone
Provide a more general freebsd_install_fdt that can install
DTS or DTB files by automatically invoking the proper compiler.
You just need to provide the source filename (which by default lives
in $FREEBSD_SRC/sys/boot/fdt/dts/) and the target path.

Use this tool to install both DTS and DTB files both on the MSDOS
partition (for U-Boot) and the UFS partition (for ubldr).
This will soon make it possible to load the FDT from U-Boot.