v2.3.4: Gadget update

What's Changed

• MAC addresses are fetched from device-tree nodes, which automatically capture OTP overrides
• Partition tables are re-read on traditional provisioning partitioning operations, fixing an apparent storage failure using the sb or fde provisioners.
• Redundant Pi3 Fastboot gadget removed

PRs

• 2.3.4: Updated fastboot gadgets by @tdewey-rpi in #349

Full Changelog: v2.3.3...v2.3.4