mtd: nand: raw: Fix (most) Kconfig indentation

One tab in general.  One tab plus two spaces for help text.

Link: https://lore.kernel.org/all/20240320090214.40465-4-ada@thorsis.com


Signed-off-by: Alexander Dahl <ada@thorsis.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>