drm/msm/dpu: Update function parameter documentation

dpu_core_irq_callback_handler() function comments seem to have become
stale and emit a warning:

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:147:
warning: Function parameter or member 'dpu_kms' not described in 'dpu_core_irq_callback_handler'
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:147:
warning: Excess function parameter 'arg' description in 'dpu_core_irq_callback_handler'

Fix by updating the documentation
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/20220210114106.290669-3-vkoul@kernel.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c

@@ -140,7 +140,7 @@ static const struct dpu_intr_reg dpu_intr_set[] = {
 
 /**
  * dpu_core_irq_callback_handler - dispatch core interrupts
- * @arg:		private data of callback handler
+ * @dpu_kms:		Pointer to DPU's KMS structure
  * @irq_idx:		interrupt index
  */
 static void dpu_core_irq_callback_handler(struct dpu_kms *dpu_kms, int irq_idx)