amd: xgbe: fix duplicate #include of linux/phy.h

The header linux/phy.h was included twice, so delete one of them.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>