Re-apply unroll=1 and 112 channels for gfx950 (#1706)

* Reapply "[SRC] Enable unroll=1 for gfx950 (#1602)" (#1667)
This reverts commit 329e13efff.

* Reapply "[GRAPH] Increase default nChannels to 112 for gfx950 (#1596)" (#1620)
This reverts commit b17338d164.

src/include/nccl_common.h

@@ -74,9 +74,10 @@ typedef enum {
 
 #define NCCL_ALGO_PROTO_IGNORE -1.0
 
-#define NCCL_NUM_UNROLLS 2 // 2/4
-#define NCCL_UNROLL_2 0
-#define NCCL_UNROLL_4 1
+#define NCCL_NUM_UNROLLS 3 // 1/2/4
+#define NCCL_UNROLL_1 0
+#define NCCL_UNROLL_2 1
+#define NCCL_UNROLL_4 2
 
 #define NCCL_NUM_FLOATS 6 // half/float/double/rccl_bfloat16/rccl_float8/rccl_bfloat8
 #endif