updatehub-rootfs-portcommand.bbclass: Allow overriding of Product UID
updatehub-rootfs-portcommand.bbclass: Allow overriding of Product UID

The UPDATEHUB_ROOTFS_PRODUCT_UID allow for override of existing UpdateHub
Product UID during rootfs generation.

Signed-off-by: Otavio Salvador <1d31b11c1b92bf5d043d36edfe7174db39a6b891@ossystems.com.br>

UpdateHub/meta-updatehub,UpdateHub/meta-updatehub,UpdateHub/meta-updatehub