If the corresponding '#xxx-cells' value is much too large, an integer
overflow can prevent the checks in check_property_phandle_args() from
correctly determining that the checked property is too short for the
given cells value. This leads to an infinite loops.
This patch fixes the bug, and adds a testcase for it. Further
information in https://github.com/dgibson/dtc/issues/64
Reported-by: Anciety <anciety@pku.edu.cn>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>