RT93137 Move the U-boot environment to the offset 128KB in eNVM.

Note that this spans a 128KB eNVM section, meaning that the free eNVM
space starts at 256KB.

include/configs/stm32f429-discovery.h

@@ -153,7 +153,7 @@
 #define CONFIG_ENV_IS_IN_ENVM
 #define CONFIG_ENV_SIZE			(4 * 1024)
 #define CONFIG_ENV_ADDR 		\
-	(CONFIG_SYS_ENVM_BASE + CONFIG_SYS_ENVM_LEN - (128 * 1024))
+	(CONFIG_SYS_ENVM_BASE + (128 * 1024))
 #define CONFIG_INFERNO			1
 #define CONFIG_ENV_OVERWRITE		1