board: ronetix: use get_nand_dev_by_index()

As part of preparation for nand DM conversion the new API has been
introduced to remove direct access to nand_info array. So, use it here
instead of accessing to nand_info array directly.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

board/ronetix/pm9261/pm9261.c

@@ -195,7 +195,7 @@ void lcd_show_board_info(void)
 
 	nand_size = 0;
 	for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
-		nand_size += nand_info[i]->size;
+		nand_size += get_nand_dev_by_index(i)->size;
 
 	flash_size = 0;
 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++)

board/ronetix/pm9263/pm9263.c

@@ -294,7 +294,7 @@ void lcd_show_board_info(void)
 
 	nand_size = 0;
 	for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
-		nand_size += nand_info[i]->size;
+		nand_size += get_nand_dev_by_index(i)->size;
 
 	flash_size = 0;
 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++)