ARM: dts: imx: Drop redundant CPU "clock-latency"

ARM: dts: imx: Drop redundant CPU "clock-latency"

The "clock-latency" property is part of the deprecated opp-v1 binding
and is redundant if the opp-v2 table has equal or larger values in any
"clock-latency-ns". The OPP tables have values of 150000, so it can be
removed.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>