resolve conflict by adding both: mips64 and riscv64

diff --cc configure.ac
index 5b7078f15d70cb02aca80420e5927b7d40153c29,060d2819dcbfa39282695007f9fc4396c12442b9..5e098aa2b595b806f5d7971f2c49ac5d1582ffe5
--- 1/configure.ac
--- 2/configure.ac
+++ b/configure.ac
@@@ -123,7 -123,7 +123,7 @@@ if test -z "$LIBPOSTFIX"; the
    case "${host_os}" in
      *linux* )
        case "${host_cpu}" in
-         aarch64 | powerpc64 | powerpc64le | s390x | x86_64 | sparc64 | mips64* )
 -        aarch64 | powerpc64 | powerpc64le | s390x | x86_64 | sparc64 | riscv64 )
++        aarch64 | powerpc64 | powerpc64le | s390x | x86_64 | sparc64 | mips64* | riscv64 )
            LIBPOSTFIX="64"
            INTGOSIZE=64
            ;;