Refactor the h3ulcb machine templates

This splits the machine templates for the h3 into three:
- h3ulcb = plain h3ulcb with graphics driver package
- h3ulcb-nogfx = plain h3ulcb without graphics driver package
- h3ulcb-kf = h3ulcb with kingfisher baseboard and graphics driver package

This improves maintainability of the h3ulcb machine targets.

Bug-AGL: SPEC-3443

Change-Id: Ibca5e7615ca5bc467ec46d4564f42363a2a5466c
Signed-off-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/24912
Reviewed-by: Stéphane Desneux <stephane.desneux@iot.bzh>