dt-bindings: phy: samsung: drop old Eynos5440 PCIe phy

The Exynos5440 PCIe phy support was removed in commit 496db029
("phy: samsung: phy-exynos-pcie: rework driver to support Exynos5433
PCIe PHY") (with its own bindings), so drop the old bindings.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220129193646.372481-2-krzysztof.kozlowski@canonical.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/samsung-phy.txt

@@ -191,20 +191,3 @@ Example:
 		usbdrdphy0 = &usb3_phy0;
 		usbdrdphy1 = &usb3_phy1;
 	};
-
-Samsung Exynos SoC series PCIe PHY controller
---------------------------------------------------
-Required properties:
-- compatible : Should be set to "samsung,exynos5440-pcie-phy"
-- #phy-cells : Must be zero
-- reg : a register used by phy driver.
-	- First is for phy register, second is for block register.
-- reg-names : Must be set to "phy" and "block".
-
-Example:
-	pcie_phy0: pcie-phy@270000 {
-		#phy-cells = <0>;
-		compatible = "samsung,exynos5440-pcie-phy";
-		reg = <0x270000 0x1000>, <0x271000 0x40>;
-		reg-names = "phy", "block";
-	};