tisdk-image: adjust to changes in rootfs_ipk class in danny
tisdk-image: adjust to changes in rootfs_ipk class in danny

So we wouldn't need to overlay the old rootfs_ipk locally.

Signed-off-by: Denys Dmytriyenko <d29de71aea38aad3a87d486929cb0aad173ae612@ti.com>

MentorEmbedded/meta-arago,MentorEmbedded/meta-arago,MentorEmbedded/meta-arago,MentorEmbedded/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago