app: aboot: initialise watch dog to catch the early kernel crashes.
app: aboot: initialise watch dog to catch the early kernel crashes.

Initialise the watch dog driver at then end of LK so that
early kernel stalls / crashes can be caught.

Change-Id: If66902365f010e9619a287f286d245e49346dd9a

Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk