dt-bindings: thermal: tsens: Fix nvmem-cell-names schema

There's a typo 'nvmem-cells-names' in the schema which means the correct
'nvmem-cell-names' in the examples are not checked. The possible values
are wrong too both in that the 2nd entry is not specified correctly and the
values are just wrong based on the dts files in the kernel.

Fixes: a877e768 ("dt-bindings: thermal: tsens: Convert over to a yaml schema")
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>