Fix bytes <-> kilobytes typo in Kconfig for ramdisk

This is a small fix for a typo in Kconfig. The default value for the block
size is 1024 bytes not 1024 kilobytes.
Signed-off-by: Christian Borntraeger <borntrae@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

drivers/block/Kconfig

@@ -406,7 +406,7 @@ config BLK_DEV_RAM_BLOCKSIZE
 	depends on BLK_DEV_RAM
 	default "1024"
 	help
-	  The default value is 1024 kilobytes.  PAGE_SIZE is a much more
+	  The default value is 1024 bytes.  PAGE_SIZE is a much more
 	  efficient choice however.  The default is kept to ensure initrd
 	  setups function - apparently needed by the rd_load_image routine
 	  that supposes the filesystem in the image uses a 1024 blocksize.