wic-tools: ensure pseudo is available

wic-tools: ensure pseudo is available

wic will attempt to use pseudo from the wic-tools sysroot to run, but it
was only sure to be in there if do_install had executed - which is not
the case if it had been restored from sstate, in which case it failed
horribly as seen when running the wic.Wic.test_fs_types and
test_mkfs_extraopts tests on the Yocto Project autobuilder recently. Add
an explicit dependency on pseudo-native to ensure it's always there.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>