mtd: rawnand: fix indentation in Kconfig

Rules about Kconfig are simple but in the raw NAND directory indentation
is somehow archaic. Fix the indentation in the whole file.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/raw/Kconfig

@@ -182,7 +182,7 @@ config MTD_NAND_DISKONCHIP_PROBE_ADDRESS
 	hex "Physical address of DiskOnChip" if MTD_NAND_DISKONCHIP_PROBE_ADVANCED
 	depends on MTD_NAND_DISKONCHIP
 	default "0"
-        ---help---
+	help
 	  By default, the probe for DiskOnChip devices will look for a
 	  DiskOnChip at every multiple of 0x2000 between 0xC8000 and 0xEE000.
 	  This option allows you to specify a single address at which to probe