xtensa: xtfpga: introduce SoC I/O bus

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: add support for KC705

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: xtfpga: disable lcd

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: xtfpga: add CY7C67300 USB controller support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>