On STM32, in case of PHY failure, usually because of the lack of 25/50 MHz REFCLK input, the Ethernet block would lock up in a while loop waiting for readiness, which will never happened.  This prevented the board from starting at all in the case of a PHY failure.  This commit adds a retry loop to avoid bricking the board if the Ethernet block is unable to start.

The existence of the network driver ioctl() method should depend on CONFIG_NETDEV_IOCTL rather than CONFIG_NETDEV_PHY_IOCTL.  The former enables the method, the later enables a subset of possible driver IOCTLs.  This change should be basically a no-operation.  The affected ioctl methods only support those subset of driver IOCTLs selected by CONFIG_NETDEV_PHY_IOCTL and the network logic will tolerate a nul ioctl method.

The existence of the network driver ioctl() method should depend on CONFIG_NETDEV_IOCTL rather than CONFIG_NETDEV_PHY_IOCTL.  The former enables the method, the later enables a subset of possible driver IOCTLs.  This change should be basically a no-operation.  The affected ioctl methods only support those subset of driver IOCTLs selected by CONFIG_NETDEV_PHY_IOCTL and the network logic will tolerate a nul ioctl method.

Rename CONFIG_STM32_STM32F40XX to CONFIG_STM32_STM32FXXXX since it is used by F4 parts other than F40x

STM32 Ethernet: Should not stm32_phyintenable() return a failure if it could not enable the PHY interrupt?

net: network drver now retains Ethernet MAC address in a union so that other link layer addresses may be used in a MULTILINK environment.

Experimental change to STM32 Ethernet driver a success.  Porting change to all other Ethernet drivers.

STM32 Ethernet: Need two work structures so that pending poll work is not lost when an interrupt occurs.

Provide a user defined callback context for irq's, such that when
registering a callback users can provide a pointer that will get
passed back when the isr is called.

Most Ethernet drviers:  Check if the poll timer is running before restarting it at the end of each TX.

arch/: Adapt all Ethernet drivers to work as though CONFIG_NET_MULTIBUFFER were set.  Remove all references to CONFIG_NET_MULTIBUFFER

arch/:  Add option to use low-priority work queue to all Ethernet drivers in arch that support CONFIG_NET_NOINTS.

net/tcp:  tcp_ipvX_bind() not actually using the ported selected with port==0.  Also removes duplicate call to pkt_input().  Issues noted by Pascal Speck.