[FEATURE] Add general asynchronous FIFO implementation

This FIFO implementation is mandatory in future designs.

Change-Id: I13366904c2d070953dec345a078b2d530ee43068
Reviewed-on: http://brateggevoat1/gerrit/1572
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Thomas Mair <thomas.mair@br-automation.com>
Reviewed-by: Joerg Zelenka <joerg.zelenka@br-automation.com>
[FEATURE] Add synchronizer with toggle transfer

Change-Id: I079da9b58fec3c2c63b773c51b1184f9895c3d27
Reviewed-on: http://brateggevoat1/gerrit/1573
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Joerg Zelenka <joerg.zelenka@br-automation.com>
[TASK] Rework openMAC toplevel

- Add reworked openMAC toplevel (openmacTop-rtl-ea.vhd)
- Use obsolete openMAC toplevel (openMAC_Ethernet.vhd) as wrapper
- Use reworked asynchronous FIFO implementation
- Add initial toplevel simulation

Change-Id: I58a843e7d11aada880640b8a85095b8f3325bd26
Reviewed-on: http://brateggevoat1/gerrit/1574
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Thomas Mair <thomas.mair@br-automation.com>
Reviewed-by: Joerg Zelenka <joerg.zelenka@br-automation.com>
[TASK] Refactor openMAC components

Refactor following components:
- openFILTER
- openHUB
- RMII to MII converter
- MAC timer
- Activity generator
- Phy management
- Memory mapped slave converter (16 to 32 bit)

Change-Id: I6d5caa7216d92e042e0351b38473b0c443e68af2
Reviewed-on: http://brateggevoat1/gerrit/1575
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Thomas Mair <thomas.mair@br-automation.com>
Reviewed-by: Joerg Zelenka <joerg.zelenka@br-automation.com>