rocr: Remove extra LibElf find_package (#767)

This should have been removed when the libelf config search
was added.

projects/rocr-runtime/runtime/hsa-runtime/CMakeLists.txt

@@ -83,7 +83,6 @@ endif() # if (ROCM_CCACHE_BUILD)
 
 ## Find external dependencies.
 find_package(PkgConfig)
-find_package(LibElf REQUIRED)
 
 find_package(LibElf CONFIG)
 if(NOT LibElf_FOUND)