axi_ethernet: Remove axiethernet_ip_handle_name var

It is completely unused.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
dma/eth: Cover more dma options

Some hardware designs had problem with different
"non-standard" dma configurations.
Check all values which bsp is working with.

Signed-off-by: Pallav Joshi <pallavj@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>