usb/isp1760: Move isp1760_run within file (prepare for next patch)

Like the previous patch, this patch has been split from the next one
for clarity.

Signed-off-by: Arvid Brodin <arvid.brodin@enea.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>