dt-bindings: thermal: sprd: Remove redundant 'maxItems'

There's no need to specify 'maxItems' with the same value as the number
of entries in 'items'. A meta-schema update will catch future cases.

Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200313214552.845-1-robh@kernel.org