iot2050: Migrate settings into board env file

Anything that is not boot-env related is better kept there by now.

At this chance, also drop a stale comment from iot2050.h

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/include/configs/iot2050.h b/include/configs/iot2050.h
index cfff46c..8dfeadd 100644
--- a/include/configs/iot2050.h
+++ b/include/configs/iot2050.h
@@ -13,12 +13,6 @@
 
 #include <linux/sizes.h>
 
-/* SPL Loader Configuration */
-
-/* U-Boot general configuration */
-#define EXTRA_ENV_IOT2050_BOARD_SETTINGS				\
-	"usb_pgood_delay=900\0"
-
 #if IS_ENABLED(CONFIG_CMD_USB)
 # define BOOT_TARGET_USB(func) \
 	func(USB, usb, 0) \
@@ -40,10 +34,9 @@
 
 #include <config_distro_bootcmd.h>
 
-#define CFG_EXTRA_ENV_SETTINGS					\
+#define CFG_EXTRA_ENV_SETTINGS						\
 	DEFAULT_LINUX_BOOT_ENV						\
-	BOOTENV								\
-	EXTRA_ENV_IOT2050_BOARD_SETTINGS
+	BOOTENV
 
 #include <configs/ti_armv7_common.h>