ARM: dts: aspeed: fp5280g2: Fix power supply address

There are two PSU on i2c11. PSU0's address is 0x58, PSU1's address is
`0x59`, not `0x5a`.

Signed-off-by: John Wang <wangzqbj@inspur.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>