[DEVICE] Adding ability to choose unroll factor at runtime (#1734)

* Adding runtime unroll factor selection via RCCL_UNROLL_FACTOR
* [BUILD] Add support for user-defined UNROLL for debugging
* Update CHANGELOG.md
* Fix COLLTRACE errors in CI
* Add debug statements for unroll and resolve warnings
* Incorporate UNROLL into ONLY_FUNCS for debugging

---------

Signed-off-by: nileshnegi <Nilesh.Negi@amd.com>
Co-authored-by: gilbertlee-amd <44450918+gilbertlee-amd@users.noreply.github.com>
Co-authored-by: Jeffrey Novotny <jnovotny@amd.com>

[ROCm/rccl commit: 9d72be7b2f]

projects/rccl/src/include/nccl_common.h

@@ -74,10 +74,5 @@ typedef enum {
 
 #define NCCL_ALGO_PROTO_IGNORE -1.0
 
-#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