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/configs/gwventana_gw5904_defconfig b/configs/gwventana_gw5904_defconfig
index 1d95fb0..9deb080 100644
--- a/configs/gwventana_gw5904_defconfig
+++ b/configs/gwventana_gw5904_defconfig
@@ -14,11 +14,11 @@
 CONFIG_SYS_I2C_MXC_I2C2=y
 CONFIG_SYS_I2C_MXC_I2C3=y
 CONFIG_CMD_EECONFIG=y
-CONFIG_CMD_GSC=y
 CONFIG_DEFAULT_DEVICE_TREE="imx6q-gw54xx"
 CONFIG_SPL_TEXT_BASE=0x00908000
 CONFIG_SPL_MMC=y
 CONFIG_SPL_SERIAL=y
+CONFIG_SPL_DRIVERS_MISC=y
 CONFIG_SPL_STACK_R_ADDR=0x18000000
 CONFIG_SPL=y
 CONFIG_ENV_OFFSET_REDUND=0xD1400