cosmetic: config: Remove empty #ifdefs

After running tools/moveconfig.py it turned out that for various boards
there are an empty #ifdef statements.

Remove them to clean u-boot source code.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/include/configs/bg0900.h b/include/configs/bg0900.h
index 832dbba..c05b06a 100644
--- a/include/configs/bg0900.h
+++ b/include/configs/bg0900.h
@@ -19,10 +19,6 @@
 #define CONFIG_FEC_MXC
 #endif
 
-/* SPI FLASH */
-#ifdef CONFIG_CMD_SF
-#endif
-
 /* Boot Linux */
 #define CONFIG_BOOTFILE		"uImage"
 #define CONFIG_BOOTCOMMAND	"bootm"
diff --git a/include/configs/dreamplug.h b/include/configs/dreamplug.h
index 28bda14..f7f9141 100644
--- a/include/configs/dreamplug.h
+++ b/include/configs/dreamplug.h
@@ -34,9 +34,6 @@
 #define CONFIG_ENV_SECT_SIZE		0x10000	/* 64k */
 #endif
 
-#ifdef CONFIG_CMD_SF
-#endif
-
 /*
  * max 4k env size is enough, but in case of nand
  * it has to be rounded to sector size
diff --git a/include/configs/ds109.h b/include/configs/ds109.h
index 07367cf..31abb4b 100644
--- a/include/configs/ds109.h
+++ b/include/configs/ds109.h
@@ -37,9 +37,6 @@
 #define CONFIG_ENV_SECT_SIZE		0x10000	/* 64k */
 #endif
 
-#ifdef CONFIG_CMD_SF
-#endif
-
 /*
  * max 4k env size is enough, but in case of nand
  * it has to be rounded to sector size
diff --git a/include/configs/km/km_arm.h b/include/configs/km/km_arm.h
index a2e9cf1..8a00ac0 100644
--- a/include/configs/km/km_arm.h
+++ b/include/configs/km/km_arm.h
@@ -34,9 +34,6 @@
 
 /* SPI NOR Flash default params, used by sf commands */
 
-#if defined CONFIG_KM_ENV_IS_IN_SPI_NOR
-#endif
-
 /* Reserve 4 MB for malloc */
 #define CONFIG_SYS_MALLOC_LEN		(4 * 1024 * 1024)