[Orc] Drop arch check in the DebugObjectManagerPlugin for ELF

Tested this with the new AArch32 backend on armv7l and it works without issues in GDB. The size of the load-address field is only 32-bit here, but we implicitly account for it by writing a ELFT::uint which is:
https://github.com/llvm/llvm-project/blob/release/16.x/llvm/include/llvm/Object/ELFTypes.h#L57

So, instead of adding a newly supported machine type, let's just drop this restriction althogether.