compositor: Move the logic of moving outputs into the core

Instead of having the backends move the remaining outputs when one is
destroyed, let the core compositor deal with that.

Signed-off-by: Zhang, Xiong Y <xiong.y.zhang@intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
3 files changed