ARM: dts: aspeed: netbmc: Delete no-hw-checksum

The ftgmac100's checksum issue has been fixed by commit 88824e3b
("net: ethernet: ftgmac100: Fix DMA coherency issue with SW checksum")
so this property is no longer required

Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>