ARM: dove: dt: revert PMU interrupt controller node

The corresponding driver didn't make it into v3.14, so we need to remove
the node.  Dove systems fail to boot with the node present and no
driver.

This node will be re-added when the driver makes it to mainline.

Reported-by: Jean-Francois Moine <moinejf@free.fr>
Tested-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>