There is some warning if TTY is not enabled, and lead to
build error, only select serial sifive if TTY enabled, and
this also makes randconfig happy.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
[paul.walmsley@sifive.com: use two leading spaces for help text to align
 with common arch/ practice]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

On selection of SOC_SIFIVE select the corresponding platform drivers.

Signed-off-by: Loys Ollivier <lollivier@baylibre.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

Create a config option for building SiFive SoC specific resources
e.g. SiFive device tree, platform drivers...

Signed-off-by: Loys Ollivier <lollivier@baylibre.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>