cm-fx6: selectable master/slave mode analog audio

Add support for operating wm8731 in slave mode (made default).
Enable wm8731 to operate in master mode by adding to kernel
bootargs: 'audmode-mst'.

Notice:
On hardware level, enabling master mode, requires changes
in the module (R104 - out, R105 - in).
wm8731: make the code more robust dealing with erroneous configuration
Workaround 2 limitations of SSI playback (slave mode):
- severe distortions playing back mono stream
- severe distortions playing back 8kHz sampling rate audio

The nature of the workaround is SSI reporting it does not
support these modes, making the player convert the audio stream
appropriately.

Reference:
mainline kernel commit
"ASoC: imx-ssi: Remove mono support"
0865a75d4166bddc533fd50831829ceefb94f9b0
ARM: i.MX6: cm-fx6: tag kernel version with -cm-fx6-3

Tag kernel vestion with -cm-fx6-3.
Save the latest default configuration with:
1) on denad governon
2) Intel(R) 82575/82576 PCI-Express Gigabit Ethernet support
3) LDB support
net: igb: add blank I211 chip support

Add blank I211 chip support.
This patch allows programming blank chip using eeproARMtool.
net: igb: add igb private data

Add igb network adapter private data that contains a device MAC address.
This approach solves the issue with an invalid MAC address read from the chip.