packagegroup-webos-extended: Introduce separate var for some deps

* makes it easier to remove unwanted components

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@palm.com>
Change-Id: Ide3eef658d8c5a29a623678156b3342a29f862d2
Reviewed-on: https://g2g.palm.com/1688
Reviewed-by: Build Verification
Reviewed-by: Martin Jansa <martin.jansa@palm.com>
Tested-by: Martin Jansa <martin.jansa@palm.com>
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>