drm/msm/dpu: Fix error recovery after failing to enable clocks

If enabling clocks fails in msm_dss_enable_clk() the code to unwind the
settings starts at 'i' which is the clock that just failed. While this
isn't harmful it does result in a number of warnings from the clock
subsystem while trying to unpreare/disable the very clock that had
just failed to prepare/enable. Skip the current failed clock during
the unwind to to avoid the extra log spew.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>