qoriq: enable Book-E Watchdog Timer

qoriq: enable Book-E Watchdog Timer

Enable PowerPC Book-E Watchdog Timer support. Having this enabled
in-kernel will result in procd starting it during boot.

This effectively solves the problem of the WDT in the Winbond W83793 chip
potentially resetting the system during sysupgrade, which could result
in an unbootable device. While the driver is modular, resulting in procd
not starting the WDT during boot (because that happens before kmod
load), the WDT handover during sysupgrade results in the WDT being
started. This normally shouldn't be a problem, but the W83793 WDT does
not like procd's defaults, nor the handover happening during sysupgrade.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>