ARM: dts: dra72-evm: remove cpsw gpio hogging and add mode-gpios

With the current implementation of GPIO hogging and with
gpio-pcf857x is built as module, ethernet doesn't work on boot
and doesn't throw any error/warning to user. Ethernet becomes
operational when inserting gpio-pcf857x module, even this time
there is no error/warning logs to user that ethernet is
operational.

When using with NFS rootfs and gpio-pcf857x as module, board
doesn't boot as it doesn't get any ip address and doesn't throw
any error/warning. To over come this, now cpsw driver tries to
get mode-gpios. When gpio-pcf857x is built as module it will
throw error, so that user can decide either to built in
gpio-pcf857x to continue with nfs boot or choose alternate rootfs
filesystem like sd/ramdisk.

When using mmc/ramdisk as root fs, cpsw will probe defer and
re-probes again when gpio-pcf857x module is inserted and ethernet
becomes operational.
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dra72-evm.dts

@@ -429,12 +429,6 @@ pcf_gpio_21: gpio@21 {
 		interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
 		interrupt-controller;
 		#interrupt-cells = <2>;
-
-		cpsw_sel_s0 {
-			gpio-hog;
-			gpios = <4 GPIO_ACTIVE_HIGH>;
-			output-low;
-		};
 	};
 
 	tlv320aic3106: tlv320aic3106@19 {
@@ -689,6 +683,7 @@ &mac {
 	pinctrl-0 = <&cpsw_default>;
 	pinctrl-1 = <&cpsw_sleep>;
 	slaves = <1>;
+	mode-gpios = <&pcf_gpio_21 4 GPIO_ACTIVE_HIGH>;
 };
 
 &cpsw_emac0 {