Merge branch 'stmmac-pci-fix-crash-on-Intel-Galileo-Gen2'

Andy Shevchenko says:

====================
stmmac: pci: Fix crash on Intel Galileo Gen2

Due to misconfiguration of PCI driver for Intel Quark the user will get
a kernel crash:

udhcpc: started, v1.26.2
stmmaceth 0000:00:14.6 eth0: device MAC address 98:4f:ee:05:ac:47
Generic PHY stmmac-a6:01: attached PHY driver [Generic PHY] (mii_bus:phy_addr=stmmac-a6:01, irq=-1)
stmmaceth 0000:00:14.6 eth0: IEEE 1588-2008 Advanced Timestamp supported
stmmaceth 0000:00:14.6 eth0: registered PTP clock
IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready

udhcpc: sending discover

stmmaceth 0000:00:14.6 eth0: Link is Up - 100Mbps/Full - flow control off
IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: stmmac_xmit+0xf1/0x1080

Fix this by adding necessary settings.

P.S. I split fix to three patches according to what each of them adds.
====================

Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: David S. Miller <davem@davemloft.net>