Create a config option for building SiFive SoC specific resources
e.g. SiFive device tree, platform drivers...
Signed-off-by: NLoys Ollivier <lollivier@baylibre.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>