drm/msm: add chip-id param

Some of the w/a or different behavior of userspace blob driver seem to
be keyed to gpu patch revision, rather than gpu-id.  So expose the full
chip-id to userspace so it can DTRT.

Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 7a11563..28ca8cd 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -73,6 +73,12 @@
 	case MSM_PARAM_GMEM_SIZE:
 		*value = adreno_gpu->gmem;
 		return 0;
+	case MSM_PARAM_CHIP_ID:
+		*value = adreno_gpu->rev.patchid |
+				(adreno_gpu->rev.minor << 8) |
+				(adreno_gpu->rev.major << 16) |
+				(adreno_gpu->rev.core << 24);
+		return 0;
 	default:
 		DBG("%s: invalid param: %u", gpu->name, param);
 		return -EINVAL;