AB_OTA_PARTITIONS: move dtbo under vendor_boot conditional

When building system-only OTA update images, dtbo partition should not
be part of such update.

Kernel build produces vmlinux, DTB, DTBO, and vendor kernel modules.
boot.img contains compressed vmlinux.
vendor_boot.img contains vendor kernel modules + DTB (device tree blob).
dtbo.img contains DTBO (device tree blob overlay).

Since DTBO goes together with DTB, DTBO should be added to AB_OTA_PARTITIONS
only when vendor_boot.img is being built.

Bug: 169968221
Change-Id: I508c2362d207ff18bae1dbc4257bddb92a09b4cd
1 file changed