spl: nand: sunxi: stop guessing the redundant u-boot offset

Use CONFIG_SYS_NAND_U_BOOT_OFFS_REDUND value instead of trying to guess
where the redundant u-boot image is based on simple (and most of the time
erroneous) heuristics.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>

# Conflicts:
#	drivers/mtd/nand/sunxi_nand_spl.c

drivers/mtd/nand/sunxi_nand_spl.c

@@ -344,26 +344,6 @@ static int nand_read_buffer(uint32_t offs, unsigned int size, void *dest)
 
 int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)
 {
-	/*
-	 * u-boot partition sits after 2 eraseblocks (spl, spl-backup), look
-	 * for backup u-boot 1 erase block further.
-	 */
-	const uint32_t eraseblock_size = CONFIG_SYS_NAND_U_BOOT_OFFS / 2;
-	const uint32_t boot_offsets[] = {
-		CONFIG_SYS_NAND_U_BOOT_OFFS,
-		CONFIG_SYS_NAND_U_BOOT_OFFS + eraseblock_size,
-	};
-	int i;
-
-	if (offs == CONFIG_SYS_NAND_U_BOOT_OFFS) {
-		for (i = 0; i < ARRAY_SIZE(boot_offsets); i++) {
-			if (nand_read_buffer(boot_offsets[i], size,
-					     dest) == 0)
-				return 0;
-		}
-		return -1;
-	}
-
 	return nand_read_buffer(offs, size, dest);
 }