drm/nouveau/i2c/g94-: return REPLY_M value on reads

This value represents the actual number of bytes recieved on the AUX
channel as the result of a read transaction.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/subdev/i2c/auxg94.c

@@ -152,6 +152,7 @@ g94_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
 			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
 		}
 		memcpy(data, xbuf, *size);
+		*size = stat & 0x0000001f;
 	}
 
 out:

drivers/gpu/drm/nouveau/nvkm/subdev/i2c/auxgm200.c

@@ -152,6 +152,7 @@ gm200_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
 			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
 		}
 		memcpy(data, xbuf, *size);
+		*size = stat & 0x0000001f;
 	}
 
 out: