[rocm-libraries] ROCm/rocm-libraries#8501 (commit 54eb5dc)

[CK] disable DPP kernels by default

## Motivation

The dpp8 instruction has been disabled in the upstream llvm-project in
the latest compiler version, so we're hitting compilation errors with
staging compiler:
<inline asm>:2:33: error: not a valid operand.
v_dot2c_f32_f16_dpp v6, v8, v7 dpp8:[0, 0, 0, 0, 0, 0, 0, 0]
                                ^
error: cannot compile inline asm
These instructions are used for fp16 gemms that are slightly faster than
dl gemms on gfx10, but are not critical.

Going to disable these kernels for now, until a better solution is
available, to unblock the builds with staging compiler.

## Technical Details

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## Test Plan

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## Test Result

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## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.