global: Migrate CONFIG_EXTRA_ENV_SETTINGS to CFG

Perform a simple rename of CONFIG_EXTRA_ENV_SETTINGS to CFG_EXTRA_ENV_SETTINGS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/README b/README
index e19aa1f..a278825 100644
--- a/README
+++ b/README
@@ -1124,7 +1124,7 @@
 		symbols.
 
 - Default Environment:
-		CONFIG_EXTRA_ENV_SETTINGS
+		CFG_EXTRA_ENV_SETTINGS
 
 		Define this to contain any number of null terminated
 		strings (variable = value pairs) that will be part of
@@ -1133,7 +1133,7 @@
 		For example, place something like this in your
 		board's config file:
 
-		#define CONFIG_EXTRA_ENV_SETTINGS \
+		#define CFG_EXTRA_ENV_SETTINGS \
 			"myvar1=value1\0" \
 			"myvar2=value2\0"