Add proper target support for newfangled sh targets.

Add proper target support for newfangled sh targets.

GCC folk in their infinite wisdom have added half-assed target support
for newer sh cores. The support is there, but of course we have no
way to actually enable the thing, so we do that with this patch.

Likewise, binutils has no idea about any of these new targets either (not
even a half-assed attempt, sadly), so we fix that up too.. now we're able
to actually build a real toolchain for sh2a_nofpu- and other more ineptly
named toolchains (and yes, there are more inept targets than that one,
really. Go look, I promise).