mtd: drop support for NAND_ECC_SOFT_BCH as "soft_bch" mapping

There isn't any difference between handling NAND_ECC_SOFT and
NAND_ECC_SOFT_BCH now. What matters is the new field called "algo".
Please note we're keeping backward DT compatibility. We are still
treating "soft_bch" value as the one setting Hamming algorithm, it's
just handled in of_get_nand_ecc_algo now.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

@@ -3977,7 +3977,6 @@ static const char * const nand_ecc_modes[] = {
 	[NAND_ECC_HW]		= "hw",
 	[NAND_ECC_HW_SYNDROME]	= "hw_syndrome",
 	[NAND_ECC_HW_OOB_FIRST]	= "hw_oob_first",
-	[NAND_ECC_SOFT_BCH]	= "soft_bch",
 };
 
 static int of_get_nand_ecc_mode(struct device_node *np)
@@ -3993,6 +3992,14 @@ static int of_get_nand_ecc_mode(struct device_node *np)
 		if (!strcasecmp(pm, nand_ecc_modes[i]))
 			return i;
 
+	/*
+	 * For backward compatibility we support few obsoleted values that don't
+	 * have their mappings into nand_ecc_modes_t anymore (they were merged
+	 * with other enums).
+	 */
+	if (!strcasecmp(pm, "soft_bch"))
+		return NAND_ECC_SOFT;
+
 	return -ENODEV;
 }