mtd: nand: Remove useless line in Kconfig

Prepare changes that will lay in this file to better express what is
NAND related and what is not in menuconfig.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/Kconfig

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 9033215..495751e 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -2,6 +2,5 @@
 	tristate
 
 source "drivers/mtd/nand/onenand/Kconfig"
-
 source "drivers/mtd/nand/raw/Kconfig"
 source "drivers/mtd/nand/spi/Kconfig"