Revert "drm/msm/a6xx: Poll for GBIF unhalt status in hw_init"

Commit f6ebff4fe810 ("drm/msm/adreno: De-spaghettify the use of memory
barriers") made some fixups relating to write arrival, ensuring that
the GPU's memory interface has *really really really* been told to come
out of reset. That in turn rendered the hacky commit being reverted no
longer necessary.

Get rid of it.

This reverts commit b7753280 ("drm/msm/a6xx: Poll for GBIF unhalt
status in hw_init")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/600870/Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/a6xx_gpu.c

@@ -867,10 +867,6 @@ static int hw_init(struct msm_gpu *gpu)
 		gpu_read(gpu, REG_A6XX_RBBM_GBIF_HALT);
 	}
 
-	/* Some GPUs are stubborn and take their sweet time to unhalt GBIF! */
-	if (adreno_is_a7xx(adreno_gpu) && a6xx_has_gbif(adreno_gpu))
-		spin_until(!gpu_read(gpu, REG_A6XX_GBIF_HALT_ACK));
-
 	gpu_write(gpu, REG_A6XX_RBBM_SECVID_TSB_CNTL, 0);
 
 	if (adreno_is_a619_holi(adreno_gpu))