ARM: socfpga: vining_fpga: Rename VINING|FPGA

The company Samtec was merged into Softing, migrate the board over to
the new name and update copyright headers.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Silvio Fricke <silvio.fricke@softing.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>