fpga: lattice-sysconfig-spi: add Lattice sysCONFIG FPGA manager

Add support to the FPGA manager for programming Lattice ECP5 FPGA over
slave SPI sysCONFIG interface.

sysCONFIG interface core functionality is separate from both ECP5 and
SPI specifics, so support for other FPGAs with different port types can
be added in the future.

Signed-off-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20221025053947.2737-2-i.bornyakov@metrotek.ru
[yilun.xu@intel.com: remove redundant blank line after kmemdup]
Signed-off-by: Xu Yilun <yilun.xu@intel.com>