drm/msm/dp: Add a missing semi-colon

drm/msm/dp: Add a missing semi-colon

A missing semicolon here causes my external display to stop working.
Indeed, missing the semicolon on the return statement leads to
dp_panel_update_tu_timings() not existing because the compiler thinks
it's part of the return statement of a void function, so it must not be
important.

  $ ./scripts/bloat-o-meter before.o after.o
  add/remove: 1/1 grow/shrink: 0/1 up/down: 7400/-7540 (-140)
  Function                                     old     new   delta
  dp_panel_update_tu_timings                     -    7400   +7400
  _dp_ctrl_calc_tu.constprop                 18024   17900    -124
  dp_panel_update_tu_timings.constprop        7416       -   -7416
  Total: Before=54440, After=54300, chg -0.26%

Add a semicolon so this function works like it used to.

Cc: Sean Paul <sean@poorly.run>
Cc: Kuogee Hsieh <khsieh@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Cc: Lee Jones <lee.jones@linaro.org>
Fixes: cc9014bf63a4 ("drm/msm/dp/dp_ctrl: Move 'tu' from the stack to the heap")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>