dt-bindings: mfd: qcom,spmi-pmic: Add PM2250

Add a compatible for PM2250, commonly found with QCM2290.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230315183819.3563704-1-konrad.dybcio@linaro.org