Default overlayroot disabling

v.redin

How to disable overlayroot and why are you enabling this? There is such string in linux dev tree:
```
bootargs = "earlycon=uart8250,mmio32,0xfeb50000 console=ttyFIQ0 irqchip.gicv3_pseudo_nmi=0 root=UUID=8fe9db2e-a7d4-4525-9d80-1015074a764a rootfstype=ext4 rw rootwait overlayroot=device:dev=PARTLABEL=userdata,fstye=ext4,mkfs=1 coherent_pool=1m systemd.gpt_auto=0 cgroup_enable=memory swapaccount=1";
```
If you delete overlayroot=device:dev=PARTLABEL=userdata,fstye=ext4,mkfs=1 from this then system will not boot, but if you working with it then system will be READONLY.

v.redin

Disabled