Fix for broken gigabit ethernet in Olimex A20-OLinuXino-LIME2

[Dario]

Hello,

On 2017/02/07, commit af2cbfd6 broke gigabit ethernet on Olimex A20-OLinuXino-LIME2. This commit likely prevents the activation of the option CONFIG_RTL8211X_PHY_FORCE_MASTER needed for proper gigabit networking. Also in a later revision this option was removed altogether from both A20-OLinuXino-Lime2_defconfig and A20-Olimex-SOM-EVB_defconfig. I only have an A20-OLinuXino-LIME2 for testing, I don't know whether it is needed in more devices.

If you need further assistance feel free to ask.

Dario