On resume, we use the DFS hardware to switch frequency index,
followed by a full training sequence on that index. Leaving
the DFS training modules enabled causes issues with the full
training done at resume. We also only needs these enabled
during a call to ddr_set_rate during runtime, so there's no
issue disabling them at the end of ddr_set_rate.
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>