This is not needed. Gentoo will collect license files into
the documentation directory in ebuild.
--- a/share/rocmcmakebuildtools/cmake/ROCMCreatePackage.cmake
+++ b/share/rocmcmakebuildtools/cmake/ROCMCreatePackage.cmake
@@ -409,7 +409,6 @@ macro(rocm_create_package)
     if(PARSE_PTH)
         rocm_parse_python_syspath(${LIB_DIR} ${PARSE_NAME})
     endif()
-    rocm_setup_license(${PARSE_HEADER_ONLY})
     if(PARSE_COMPONENTS)
         rocm_set_comp_cpackvar(PARSE_HEADER_ONLY "${PARSE_COMPONENTS}")
     endif()