mtd: nand: realtek-ecc: Fix Kconfig dependencies

The driver uses DMA but does not mark it as a prerequisite in
Kconfig. As it is also defined with COMPILE_TEST, autobuilders complain
about certain symbols not being available when linking on architectures
without DMA support (?) like sh.

Reported-by: kernel test robot <[e-mail]>
Closes: https://lore.kernel.org/oe-kbuild-all/[e-mail]
Cc: Markus Stockhausen <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>

drivers/mtd/nand/Kconfig

···
 
 config MTD_NAND_ECC_REALTEK
         tristate "Realtek RTL93xx hardware ECC engine"
-        depends on HAS_IOMEM
+        depends on HAS_IOMEM && HAS_DMA
         depends on MACH_REALTEK_RTL || COMPILE_TEST
         select MTD_NAND_ECC
         help