By removing the core bsps from meta-zephyr-bsp, we reintroduce build
issues caused by non-complete MACHINEOVERRIDES. This brings the needed
MACHINEOVERRIDES back into meta-zephyr.

Upstream-Status: Pending
Fixes oniro#190

Signed-off-by: Eilís Ní Fhlannagáin <elizabeth.flanagan@huawei.com>