wic-image-minimal: use uuid for root partition

wic-image-minimal: use uuid for root partition

Used --uuid option to generate PARTUUID for root partion and
gpt partition type. As this image is used in runtime testing
under qemu it makes sense to ensure that this way of specifying
root partition works.

Added dependency to gptfdisk-native to wic-image-minimal recipe to
be able to create gpt partition table.

(From OE-Core rev: ba82867bfda54e86e1de5dc4a6ad7246254cf5c3)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>