drm/msm/dpu: Assign missing writeback log_mask

The WB debug log mask ended up never being assigned, leading to writes
to this block to never be logged even if the mask is enabled in
dpu_hw_util_log_mask via debugfs.

Fixes: 84a33d0 ("drm/msm/dpu: add dpu_hw_wb abstraction for writeback blocks")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/533860/
Link: https://lore.kernel.org/r/20230418-dpu-drop-useless-for-lookup-v3-1-e8d869eea455@somainline.org
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Author: MarijnS95

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

@@ -61,6 +61,7 @@ static const struct dpu_wb_cfg *_wb_offset(enum dpu_wb wb,
 	for (i = 0; i < m->wb_count; i++) {
 		if (wb == m->wb[i].id) {
 			b->blk_addr = addr + m->wb[i].base;
+			b->log_mask = DPU_DBG_MASK_WB;
 			return &m->wb[i];
 		}
 	}