[FEATURE] Add openPOWERLINK Ethernet driver for Realtek-8111/8168

Add openPOWERLINK Ethernet driver for Realtek-8111/8168.

Signed-off-by: Josef Baumgartner <josef.baumgartner@br-automation.com>

Change-Id: I9d9f445c737eb6a83e0f4000f6286711cec41d0b