clocksource/drivers/arm_arch_timer: Add dt binding for hisilicon-161010101 erratum

This erratum describes a bug in logic outside the core, so MIDR can't be
used to identify its presence, and reading an SoC-specific revision
register from common arch timer code would be awkward.  So, describe it
in the device tree.
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Documentation/devicetree/bindings/arm/arch_timer.txt

@@ -31,6 +31,12 @@ to deliver its interrupts via SPIs.
   This also affects writes to the tval register, due to the implicit
   counter read.
 
+- hisilicon,erratum-161010101 : A boolean property. Indicates the
+  presence of Hisilicon erratum 161010101, which says that reading the
+  counters is unreliable in some cases, and reads may return a value 32
+  beyond the correct value. This also affects writes to the tval
+  registers, due to the implicit counter read.
+
 ** Optional properties:
 
 - arm,cpu-registers-not-fw-configured : Firmware does not initialize