[BUILD] Update gfxTargets for ASAN build

[nileshnegi]

Details

Work item: Internal

What were the changes?

• Modify RCCL build for Address Sanitizer (ASAN)-enabled builds to only target GPU architectures with xnack+.
• Remove older GPU architectures like gfx803, gfx900 from the DEFAULT_GPUS list as they are no longer supported by AMD.

Why were the changes made?
Device-side address sanitizer instrumentation requires xnack+. Because of this, the gfxTargets included in the ASAN builds should include only xnack+ targets.
Additionally, this saves build time by removing any non-xnack+ targets.

How was the outcome achieved?
If ASAN is enabled, modify the GPU target list in CMakeLists.txt by appending xnack+ to the default list of GPU targets (or, if defined, local GPU target).

Approval Checklist

Do not approve until these items are satisfied.

• [ ] Verify the CHANGELOG has been updated, if
  • there are any NCCL API version changes,
  • any changes impact library users, and/or
  • any changes impact any other ROCm library.