drm/msm/a6xx: Use descriptive bitfield names for CP_PROTECT_CNTL

We have the necessary information, so explain which bit does what.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/543332/Signed-off-by: Rob Clark <robdclark@chromium.org>

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

@@ -930,7 +930,10 @@ static void a6xx_set_cp_protect(struct msm_gpu *gpu)
 	 * protect violation and select the last span to protect from the start
 	 * address all the way to the end of the register address space
 	 */
-	gpu_write(gpu, REG_A6XX_CP_PROTECT_CNTL, BIT(0) | BIT(1) | BIT(3));
+	gpu_write(gpu, REG_A6XX_CP_PROTECT_CNTL,
+		  A6XX_CP_PROTECT_CNTL_ACCESS_PROT_EN |
+		  A6XX_CP_PROTECT_CNTL_ACCESS_FAULT_ON_VIOL_EN |
+		  A6XX_CP_PROTECT_CNTL_LAST_SPAN_INF_RANGE);
 
 	for (i = 0; i < count - 1; i++)
 		gpu_write(gpu, REG_A6XX_CP_PROTECT(i), regs[i]);