binutils: Do not build gold linker on mips/glibc

Using gnu_hash style is unsupported on gold for now therefore disable
building gold on mips/glibc

Certain applications poke for presence of gold linker and silently use
it (webkit), therefore its best to disable building it

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>