dt-bindings: pinctrl: qcom-pmic-gpio: add qcom,pmi8998-gpio binding

Add support for the PMI8998 GPIO variant to the Qualcomm PMIC GPIO
binding document.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.txt

@@ -19,6 +19,7 @@ PMIC's from Qualcomm.
 		    "qcom,pm8998-gpio"
 		    "qcom,pma8084-gpio"
 		    "qcom,pmi8994-gpio"
+		    "qcom,pmi8998-gpio"
 		    "qcom,pms405-gpio"
 
 		    And must contain either "qcom,spmi-gpio" or "qcom,ssbi-gpio"