board: gateworks: venice: use common GSC driver

Use the common GSC driver.

This allows us to do some additional cleanup:
 - rename gsc{.c,.h} to eeprom{.c.h} for clarity
 - collapse eeprom_get_dev
 - remove unnecessary header files and alphabatize includes

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/arch/arm/dts/imx8mm-venice.dts b/arch/arm/dts/imx8mm-venice.dts
index 54505a0..39b0306 100644
--- a/arch/arm/dts/imx8mm-venice.dts
+++ b/arch/arm/dts/imx8mm-venice.dts
@@ -27,6 +27,13 @@
 	pinctrl-0 = <&pinctrl_i2c1>;
 	status = "okay";
 
+	gsc: gsc@20 {
+		compatible = "gw,gsc";
+		reg = <0x20>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
 	eeprom@51 {
 		compatible = "atmel,24c02";
 		reg = <0x51>;