elemental-post-build-generate-rpi-image-0.4-160000.2.2

- handle non-iso builds gracefully

- Adapt to new rootfs.squashfs file path

- install to /usr/lib/build/post_build.d

- Copying required files only <EFI>/boot path. This prevents
  dereferencing multiple links pointing to the same file, otherwise
  kernel and initrd are duplicated.

- fix flavor extraction (micro version was added to filename)

- follow symlinks when copying boot partition

- Fix generator script: Do not patch partition label setup from
  grub.cfg.

- fix grub2 root partition (rancher/elemental#1151)

- switch ttyS0 baudrate to 115200 (standard for Raspberry Pi)
  (rancher/elemental#1139)

- iso name changed, adapt flavor extraction
- handle empty flavor