Move the emaclite Config object from stack to heap.

Move the emaclite Config object from the stack into dynamically
allocated memory. The Xilinx backend does not copy this struct,
instead it keeps pointer for future use.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>