[QEMU][BOOTSCRIPT] move qemu-local to meta-seco-clea-os, add bootscript
This reverts commit 8c5c2a1b, as the qemu bbclass was moved to meta-seco-clea-os.
Also add bootscript and boot environment for qemuarm and qemuarm64.
Known issue: missing GRUB boot script for qemux86 and qemux86-64.
Edited by Alessandro Pecugi