Fix ARM64 arch name for rpm.

Author: MrMYHuang

ci/build.sh

@@ -89,8 +89,12 @@ if [ "$ARCH" == "arm64" ]; then
         "-DCMAKE_C_COMPILER=clang-8"
         "-DCMAKE_CXX_COMPILER=clang++-8"
     )
+    # RPM-based Linux distributions use aarch64 instead of arm64 as ARM64 architecture name.
+    ARCH="aarch64"
 fi
 
+export CPACK_RPM_PACKAGE_ARCHITECTURE="${ARCH}"
+
 cmake "$REPO_ROOT" "${cmake_args[@]}" 
 
 # now, compile