drm/msm: Use div64_ul instead of do_div

Fix following coccicheck warning:
drivers/gpu/drm/msm/msm_gpu_devfreq.c:72:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead.

Use div64_ul instead of do_div to avoid a possible truncation.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Patchwork: https://patchwork.freedesktop.org/patch/483499/
Link: https://lore.kernel.org/r/20220426132126.686447-1-wanjiabing@vivo.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>