drm/msm/adreno: Fix warn splat for devices without revn

Recently, a WARN_ON() was introduced to ensure that revn is filled before
adreno_is_aXYZ is called. This however doesn't work very well when revn is
0 by design (such as for A635).

Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Fixes: cc943f43 ("drm/msm/adreno: warn if chip revn is verified before being set")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280
Patchwork: https://patchwork.freedesktop.org/patch/545554/

drivers/gpu/drm/msm/adreno/adreno_gpu.h

@@ -149,7 +149,8 @@ bool adreno_cmp_rev(struct adreno_rev rev1, struct adreno_rev rev2);
 
 static inline bool adreno_is_revn(const struct adreno_gpu *gpu, uint32_t revn)
 {
-	WARN_ON_ONCE(!gpu->revn);
+	/* revn can be zero, but if not is set at same time as info */
+	WARN_ON_ONCE(!gpu->info);
 
 	return gpu->revn == revn;
 }
@@ -161,14 +162,16 @@ static inline bool adreno_has_gmu_wrapper(const struct adreno_gpu *gpu)
 
 static inline bool adreno_is_a2xx(const struct adreno_gpu *gpu)
 {
-	WARN_ON_ONCE(!gpu->revn);
+	/* revn can be zero, but if not is set at same time as info */
+	WARN_ON_ONCE(!gpu->info);
 
 	return (gpu->revn < 300);
 }
 
 static inline bool adreno_is_a20x(const struct adreno_gpu *gpu)
 {
-	WARN_ON_ONCE(!gpu->revn);
+	/* revn can be zero, but if not is set at same time as info */
+	WARN_ON_ONCE(!gpu->info);
 
 	return (gpu->revn < 210);
 }