dt-bindings: timer: Convert rda,8810pl-timer to YAML

Convert RDA Micro Timer bindings to DT schema format.

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220504175502.GA2573@standask-GA-A55M-S2HP