adding support for .wic .wic.xz as source for image

adding support for .wic .wic.xz as source for image

Change-Id: I94c09c6105ac06a37cedc04c777dd1372015a02d
Signed-off-by: Dominig ar Foll Intel Open Source <dominig.arfoll@fridu.net>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/12263
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-boot-test: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>