ARM: 7762/1: kernel: fix arm_dt_init_cpu_maps() to skip non-cpu nodes

The introduction of the cpu-map topology node in the cpus node implies
that cpus node might have children that are not cpu nodes. The DT
parsing code needs updating otherwise it would check for cpu nodes
properties in nodes that are not required to contain them, resulting
in warnings that have no bearing on bindings defined in the dts source file.

Change-Id: I19a999e353873ddf1af0f921588591d842eff53c
Cc: <stable@vger.kernel.org> [3.8+]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>