Simplify defining the linker architecture macro.

Like the new TODO says, though, do we need this at all? Wouldn't we be better
off just using the regular architecture-specific macros? This is a dynamic
linker, so there's never a possibility of cross-linking.

Change-Id: I7be6b8663f5e585c4024a49aae383430c86a3c1b
1 file changed