remove --hash-style option from linker command line

The .gnu.hash ELF section is not available on MIPS,
therefore this option must not be added unconditionally.
Rely on the linker's default instead.

Task-number: QBS-696
Change-Id: Ib31f6087a24b35e7fb0110fe777e03050b06c412
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>