scripts: runner: dfu-util: support DT-based flashing for DfuSe

Enable DT support in the dfu-util flasher when the target is a
DfuSe (DFU + ST extensions) device.

Untangling DfuSe-specific options (currently, the default is 'leave',
to immediately start running after the flashing is done) from the
actual address makes this cleaner, and sets up a subsequent patch to
let callers set DfuSe options.

It also lets us fix an unnecessary printline when flashing DfuSe
devices. There's no need to reset those, since the 'leave' modifier
starts execution immediately.

Signed-off-by: Marti Bolivar <marti@opensourcefoundries.com>
2 files changed