gpio: sandbox: cleanup binding support

Cleanup binding support, use the generic binding by default
(test u-class gpio_xlate_offs_flags function) and add
specific binding for added value.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 02e37ab..f5f43eb 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -1,5 +1,8 @@
 /dts-v1/;
 
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/gpio/sandbox-gpio.h>
+
 / {
 	model = "sandbox";
 	compatible = "sandbox";
@@ -86,11 +89,14 @@
 		ping-expect = <0>;
 		ping-add = <0>;
 		u-boot,dm-pre-reloc;
-		test-gpios = <&gpio_a 1>, <&gpio_a 4>, <&gpio_b 5 0 3 2 1>,
+		test-gpios = <&gpio_a 1>, <&gpio_a 4>,
+			<&gpio_b 5 GPIO_ACTIVE_HIGH 3 2 1>,
 			<0>, <&gpio_a 12>;
-		test2-gpios = <&gpio_a 1>, <&gpio_a 4>, <&gpio_b 6 1 3 2 1>,
-			<&gpio_b 7 2 3 2 1>, <&gpio_b 8 4 3 2 1>,
-			<&gpio_b 9 0xc 3 2 1>;
+		test2-gpios = <&gpio_a 1>, <&gpio_a 4>,
+			<&gpio_b 6 GPIO_ACTIVE_LOW 3 2 1>,
+			<&gpio_b 7 GPIO_IN 3 2 1>,
+			<&gpio_b 8 GPIO_OUT 3 2 1>,
+			<&gpio_b 9 (GPIO_OUT|GPIO_OUT_ACTIVE) 3 2 1>;
 		int-value = <1234>;
 		uint-value = <(-1234)>;
 		int64-value = /bits/ 64 <0x1111222233334444>;