This patch ensures that even if no environment partition is present on a Neo1973
device, the USB serial emulation will be the default console, not the serial port.

This enables people with no debug board to always access the u-boot console, even
if their environment partition is gone.

The only remaining case of bootloader lock-out is now when the environment
contains stdin/stdout/stderr=serial settings.

Index: u-boot/include/configs/neo1973_gta01.h
===================================================================
--- u-boot.orig/include/configs/neo1973_gta01.h
+++ u-boot/include/configs/neo1973_gta01.h
@@ -182,6 +182,7 @@
 
 #define CONFIG_EXTRA_ENV_SETTINGS 					\
 	"usbtty=cdc_acm\0"						\
+	"stderr=usbtty\0stdout=usbtty\0stdin=usbtty\0"			\
 	"bootargs_base=rootfstype=jffs2 root=/dev/mtdblock4 console=ttySAC0,115200 console=tty0 loglevel=8\0" \
 	""
 
Index: u-boot/include/configs/neo1973_gta02.h
===================================================================
--- u-boot.orig/include/configs/neo1973_gta02.h
+++ u-boot/include/configs/neo1973_gta02.h
@@ -189,6 +189,7 @@
 
 #define CONFIG_EXTRA_ENV_SETTINGS 					\
 	"usbtty=cdc_acm\0"						\
+	"stderr=usbtty\0stdout=usbtty\0stdin=usbtty\0"			\
 	"bootargs_base=rootfstype=jffs2 root=/dev/mtdblock6 console=ttySAC2,115200 console=tty0 loglevel=8\0" \
 	""