dt-bindings: PCI: qcom: Add ext reset

Document ext reset used in ipq8064 SoC by qcom PCIe driver.

Link: https://lore.kernel.org/r/20200615210608.21469-6-ansuelsmth@gmail.comSigned-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>

Documentation/devicetree/bindings/pci/qcom,pcie.txt

@@ -179,6 +179,7 @@
 			- "pwr"			PWR reset
 			- "ahb"			AHB reset
 			- "phy_ahb"		PHY AHB reset
+			- "ext"			EXT reset
 
 - reset-names:
 	Usage: required for ipq8074
@@ -287,8 +288,9 @@
 			 <&gcc PCIE_HCLK_RESET>,
 			 <&gcc PCIE_POR_RESET>,
 			 <&gcc PCIE_PCI_RESET>,
-			 <&gcc PCIE_PHY_RESET>;
-		reset-names = "axi", "ahb", "por", "pci", "phy";
+			 <&gcc PCIE_PHY_RESET>,
+			 <&gcc PCIE_EXT_RESET>;
+		reset-names = "axi", "ahb", "por", "pci", "phy", "ext";
 		pinctrl-0 = <&pcie_pins_default>;
 		pinctrl-names = "default";
 	};