board: gateworks: gw_ventana: use comomn GSC driver

Use the common GSC driver.

This allows us to do some additional cleanup:
 - use the GSC driver functions
 - move waiting for the EEPROM to the SPL int (it will always be ready
   after this)
 - move eeprom functions into eeprom file and elimate GSC_I2C_BUS
 - eliminate some redundant EEPROM reads (the EEPROM must be read in
   SPL before relocation, in SPL after relocation, and in U-Boot init.
   All subsequent uses can use the global structure)
 - remove unnecessary header files and alphabatize includes

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/arch/arm/mach-imx/mx6/Kconfig b/arch/arm/mach-imx/mx6/Kconfig
index 3d675fc..947b73f 100644
--- a/arch/arm/mach-imx/mx6/Kconfig
+++ b/arch/arm/mach-imx/mx6/Kconfig
@@ -227,6 +227,8 @@
 	bool "gw_ventana"
 	depends on MX6QDL
 	select SUPPORT_SPL
+	select GATEWORKS_SC
+	select MISC
 	imply CMD_SATA
 	imply CMD_SPL