ixgbe: cleanup defines

#define IXGBE_MAX_RXD			   4096

#define IXGBE_MIN_RXD			     64

#define IXGBE_DEFAULT_RXQ			   1

#define IXGBE_MAX_RXQ				   1

#define IXGBE_MIN_RXQ				   1

/* flow control */

#define IXGBE_DEFAULT_FCRTL		0x10000

#define IXGBE_MIN_FCRTL			   0x40

#define MAXIMUM_ETHERNET_VLAN_SIZE (ETH_FRAME_LEN + ETH_FCS_LEN + VLAN_HLEN)

/* How many Tx Descriptors do we need to call netif_wake_queue? */

#define IXGBE_TX_QUEUE_WAKE 16

/* How many Rx Buffers do we bundle into one write to the hardware ? */

#define IXGBE_RX_BUFFER_WRITE	16	/* Must be power of 2 */