ARM: dts: qcom: use generic node name "gpio" in SPMI PMIC

GPIO controller nodes are named by convention just "gpio", not "gpios".

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220908080938.29199-1-krzysztof.kozlowski@linaro.org