drm/msm/dpu: Update the comment style

The multi line comment style is wrongly used as kernel-doc comment. This
gives a warning:

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:17:
warning: This comment starts with '/**', but isn't a kernel-doc comment.
Refer Documentation/doc-guide/kernel-doc.rst

Update the style to fix this.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20220210114106.290669-2-vkoul@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>