Nokia RX-51: Remove old comments from configs/nokia_rx51.h file

These comments are relict for old, now removed config options.
So remove these obsoleted comments too.
Signed-off-by: NPali Rohár <pali@kernel.org>

include/configs/nokia_rx51.h

@@ -75,12 +75,6 @@
 #define CONFIG_USBD_MANUFACTURER	"Nokia"
 #define CONFIG_USBD_PRODUCT_NAME	"N900"
 
-/* commands to include */
-
-/*
- * TWL4030
- */
-
 #define GPIO_SLIDE			71
 
 /*
@@ -229,10 +223,6 @@ int rx51_kp_getc(struct stdio_dev *sdev);
 	"run attachboot;" \
 	"echo"
 
-/*
- * Miscellaneous configurable options
- */
-
 /* default load address */
 #define CONFIG_SYS_LOAD_ADDR		(OMAP34XX_SDRC_CS0)