[RCCL] Detect ROCm version via core symlink for multi-arch

 installs (#7011)

## Motivation

Allow RCCL to configure against ROCm installs that use the new
multi-arch packaging layout where .info/version is not at the top level
of ROCM_PATH.

## Technical Details

In projects/rccl/CMakeLists.txt, the ROCm version detection now reads
${ROCMCORE_PATH}/.info/version and falls back to
${ROCMCORE_PATH}/core/.info/version (the core alternatives symlink) when
the former is absent.

## JIRA ID

AICOMRCCL-1247

## Test Plan

Configured RCCL with CMake against a multi-arch /opt/rocm (7.13.0)
install that lacks a top-level .info/version.

## Test Result

CMake now reads the version from /opt/rocm/core/.info/version and
reports ROCm version: 7.13.0 instead of failing at the file(READ ...)
step.

## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
[rocm-systems] ROCm/rocm-systems#7011 (commit c79a53e)

Author: atulkulk

CMakeLists.txt

@@ -222,8 +222,16 @@ endif()
 if(EXPLICIT_ROCM_VERSION)
   set(rocm_version_string "${EXPLICIT_ROCM_VERSION}")
 elseif(ROCMCORE_PATH)
-  message(STATUS "Reading ROCM version from ${ROCMCORE_PATH}/.info/version")
-  file(READ "${ROCMCORE_PATH}/.info/version" rocm_version_string)
+  # Use .info/version directly, or under the 'core' symlink for multi-arch installs.
+  set(rocm_info_version_file "${ROCMCORE_PATH}/.info/version")
+  if(NOT EXISTS "${rocm_info_version_file}")
+    set(rocm_info_version_file "${ROCMCORE_PATH}/core/.info/version")
+  endif()
+  if(NOT EXISTS "${rocm_info_version_file}")
+    message(FATAL_ERROR "Could not determine ROCm version: expected '${ROCMCORE_PATH}/.info/version' or '${ROCMCORE_PATH}/core/.info/version' (set EXPLICIT_ROCM_VERSION or set ROCMCORE_PATH to a valid installation)")
+  endif()
+  message(STATUS "Reading ROCM version from ${rocm_info_version_file}")
+  file(READ "${rocm_info_version_file}" rocm_version_string)
 else()
   message(FATAL_ERROR "Could not determine ROCM version (set EXPLICIT_ROCM_VERSION or set ROCM_PATH to a valid installation)")
 endif()