[rocm-libraries] ROCm/rocm-libraries#5095 (commit 7e55766)

[CK_TILE] Enable MXFP6 for MX GEMM op

## Motivation

Add support for MXFP6 in the MX GEMM op in CK-Tile.

Depends on https://github.com/ROCm/rocm-libraries/pull/4594

## 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.

include/ck_tile/host/fill.hpp

@@ -169,6 +169,41 @@ struct FillUniformDistribution<ck_tile::pk_int4_t>
     }
 };
 
+template <>
+struct FillUniformDistribution<ck_tile::pk_fp6x16_t>
+{
+    float a_{-2.f};
+    float b_{2.f};
+    std::optional<uint32_t> seed_{11939};
+
+    template <typename ForwardIter>
+    void operator()(ForwardIter first, ForwardIter last) const
+    {
+        std::mt19937 gen(seed_.has_value() ? *seed_ : std::random_device{}());
+        std::uniform_real_distribution<float> dis(a_, b_);
+        while(first != last)
+        {
+            ck_tile::pk_fp6x16_t pk{};
+            for(ck_tile::index_t i = 0; i < ck_tile::pk_fp6x16_t::packed_size; ++i)
+            {
+                pk.pack(ck_tile::pk_fp6x16_t::float_to_fp6_e2m3(dis(gen)), i);
+            }
+            *first = pk;
+            ++first;
+        }
+    }
+
+    template <typename ForwardRange>
+    auto operator()(ForwardRange&& range) const
+        -> std::void_t<decltype(std::declval<const FillUniformDistribution&>()(
+            std::begin(std::forward<ForwardRange>(range)),
+            std::end(std::forward<ForwardRange>(range))))>
+    {
+        (*this)(std::begin(std::forward<ForwardRange>(range)),
+                std::end(std::forward<ForwardRange>(range)));
+    }
+};
+
 namespace impl {
 
 // clang-format off