cfi_flash: Fix devicetree address determination

The cfi-flash driver uses an open-coded version of the generic
algorithm to decode and translate multiple frames of a "reg" property.

This starts off the wrong foot by using the address-cells and size-cells
properties of *this* very node, and not of the parent. This somewhat
happened to work back when we were using a wrong default size of 2,
but broke about a year ago with commit 0ba41ce1 ("libfdt: return
correct value if #size-cells property is not present").

Instead of fixing the reinvented wheel, just use the generic function
that does all of this properly.

This fixes U-Boot on QEMU (-arm64), which was crashing due to decoding
a wrong flash base address:
DRAM:  1 GiB
Flash: "Synchronous Abort" handler, esr 0x96000044
elr: 00000000000211dc lr : 00000000000211b0 (reloc)
elr: 000000007ff5e1dc lr : 000000007ff5e1b0
x0 : 00000000000000f0 x1 : 000000007ff5e1d8
x2 : 000000007edfbc48 x3 : 0000000000000000
x4 : 0000000000000000 x5 : 00000000000000f0
x6 : 000000007edfbc2c x7 : 0000000000000000
x8 : 000000007ffd8d70 x9 : 000000000000000c
x10: 0400000000000003 x11: 0000000000000055
     ^^^^^^^^^^^^^^^^
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Reviewed-by: NStefan Roese <sr@denx.de>

drivers/mtd/cfi_flash.c

@@ -2468,29 +2468,17 @@ unsigned long flash_init(void)
 #ifdef CONFIG_CFI_FLASH /* for driver model */
 static int cfi_flash_probe(struct udevice *dev)
 {
-	const fdt32_t *cell;
-	int addrc, sizec;
-	int len, idx;
+	fdt_addr_t addr;
+	int idx;
 
-	addrc = dev_read_addr_cells(dev);
-	sizec = dev_read_size_cells(dev);
-
-	/* decode regs; there may be multiple reg tuples. */
-	cell = dev_read_prop(dev, "reg", &len);
-	if (!cell)
-		return -ENOENT;
-	idx = 0;
-	len /= sizeof(fdt32_t);
-	while (idx < len) {
-		phys_addr_t addr;
-
-		addr = dev_translate_address(dev, cell + idx);
+	for (idx = 0; idx < CFI_MAX_FLASH_BANKS; idx++) {
+		addr = dev_read_addr_index(dev, idx);
+		if (addr == FDT_ADDR_T_NONE)
+			break;
 
 		flash_info[cfi_flash_num_flash_banks].dev = dev;
 		flash_info[cfi_flash_num_flash_banks].base = addr;
 		cfi_flash_num_flash_banks++;
-
-		idx += addrc + sizec;
 	}
 	gd->bd->bi_flashstart = flash_info[0].base;