Hello,
I don't really understand your problem. Where is your issue ?
If the problem is why there is "Flash: 64 MiB" with RZ RSK and why there is "Flash: ## Unknown flash on Bank 1 - Size = 0x00000000 = 0 MB" with my custom board ?
Does your custom board have a NOR flash ? If not, I suggest you to define CONFIG_SYS_NO_FLASH in include/configs/your_board.h file. It will tell U-boot you don't have a NOR flash in your board.
QSPI and Nor flash are two different things.