imx8mp-var-som-symphony: Add gpio-hog-optional property to pca9534 gp…

…io-hogs

Custom carrier boards without pca9534 fail to boot with the following
errors:

> pca953x gpio@20: Error reading output register
> Failed to probe device usb3_sel err: -121
> pca953x gpio@20: Error reading output register
> Failed to probe device eth1_phy_rst err: -121
> pca953x gpio@20: Error reading output register
> Failed to probe device eth1_phy_vsel err: -121
> pca953x gpio@20: Error reading output register
> Failed to probe device eth1_phy_pwr err: -121
> initcall sequence 00000000fffc8e18 failed at call 000000004023b320 (err=-121)
> ### ERROR ### Please RESET the board ###

gpio-hog-optional allows the boot process to continue even when the pca953x
gpio-hogs fail to probe.

Signed-off-by: Nate Drude <nate.d@variscite.com>

arch/arm/dts/imx8mp-var-som-symphony.dts

@@ -68,27 +68,31 @@
 
 		usb3_sel_hog {
 			gpio-hog;
+			gpio-hog-optional;
 			gpios = <4 0>;
 			output-low;
 			line-name = "usb3_sel";
 		};
 
 		eth1_phy_rst_hog {
 			gpio-hog;
+			gpio-hog-optional;
 			gpios = <5 0>;
 			output-high;
 			line-name = "eth1_phy_rst";
 		};
 
 		eth1_phy_vsel_hog {
 			gpio-hog;
+			gpio-hog-optional;
 			gpios = <6 0>;
 			output-high;
 			line-name = "eth1_phy_vsel";
 		};
 
 		eth1_phy_pwr_hog {
 			gpio-hog;
+			gpio-hog-optional;
 			gpios = <7 0>;
 			output-high;
 			line-name = "eth1_phy_pwr";