selftests: add uuidgen to RDEPENDS
selftests: add uuidgen to RDEPENDS

Kselftests net/rtnetlink.sh fails due to uuidgen isn't installed into
the rootfs:
./rtnetlink.sh: line 280: uuidgen: command not found

Signed-off-by: Anders Roxell <b4e8e89057bc64bc4f9625a4a821c9ac177a7ed2@linaro.org>

96boards/meta-rpb,96boards/meta-rpb