dt-bindings: input: qcom,pm8921-keypad: convert to YAML format

Convert the bindings for the keypad subdevices of Qualcomm PM8921 and
PM8058 PMICs from text to YAML format.

While doing the conversion also drop the linux,keypad-no-autorepeat
The property was never used by DT files. Both input and DT binding
maintainers consider that bindings should switch to assertive
(linux,autorepeat) instead of negating (no-autorepeat) property.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230928110309.1212221-2-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Herring <robh@kernel.org>