xtensa: xtfpga: use CONFIG_USE_OF instead of CONFIG_OF

[ Upstream commit f3d7c2cd

 ]

Use platform data to initialize xtfpga device drivers when CONFIG_USE_OF
is not selected. This fixes xtfpga networking when CONFIG_USE_OF is not
selected but CONFIG_OF is.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>