Move literal ""_uz & ""_zu into namespace 'ck::literals' (#354)

* Move literal ""_uz & ""_zu into namespace 'literals'

* Move namespace 'literals' as 'ck::literals'

[ROCm/composable_kernel commit: a670a5a092]

library/include/ck/library/utility/literals.hpp

@@ -3,6 +3,8 @@
 
 #pragma once
 
+namespace ck {
+namespace literals {
 // [P0330] Literal Suffix for (signed) size_t (C++23)
 // ref: https://wg21.link/p0330r8
 inline constexpr std::size_t operator""_uz(unsigned long long size)
@@ -14,3 +16,5 @@ inline constexpr std::size_t operator""_zu(unsigned long long size)
 {
     return static_cast<std::size_t>(size);
 }
+} // namespace literals
+} // namespace ck