ARM: at91/dt: keep watchdog running in idle mode

ARM: at91/dt: keep watchdog running in idle mode

Since turning on idle-halt in commit fe46aa679f12 (ARM: at91/dt: add
sam9 watchdog default options to SoCs), SoCs compatible with at91sam9260-wdt
no longer reboot if the watchdog times out while the CPU is in idle state.
Removing the 'idle-halt' flag that was set by default fixes this.

Signed-off-by: Michel Marti <[email protected]>
Acked-by: Boris Brezillon <[email protected]>
Acked-by: Sylvain Rochet <[email protected]>
[[email protected]: rework the commit message]
Signed-off-by: Nicolas Ferre <[email protected]>