imx: ventana: add usb_pgood_delay 2sec default

We have encountered many USB storage devices that require more warm-up
than the spec allows for.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

include/configs/gw_ventana.h

@@ -326,6 +326,7 @@
 	"dio0:mode=gpio;dio1:mode=gpio;dio2:mode=gpio;dio3:mode=gpio\0" \
 
 #define CONFIG_EXTRA_ENV_SETTINGS_COMMON \
+	"usb_pgood_delay=2000\0" \
 	"console=ttymxc1\0" \
 	"bootdevs=usb mmc sata flash\0" \
 	HWCONFIG_DEFAULT \