ARM: dts: aspeed: fp5280g2: Use the 64M layout

Use the 64M layout since the flash on the board is 64M

Signed-off-by: John Wang <wangzhiqiang02@inspur.com>
Link: https://lore.kernel.org/r/20211014072743.939293-1-wangzhiqiang02@inspur.com


Signed-off-by: Joel Stanley <joel@jms.id.au>