Add missing soft fpu units to buildrtl

rtl/amiga/buildrtl.pp

@@ -5,7 +5,7 @@ unit buildrtl;
     uses
       si_prc,
       athreads, dos, sysutils,
-
+      softfpu, sfpux80, ufloatx80, sfpu128, ufloat128,
       ctypes, strings,
       rtlconsts, sysconst, math, types,
       typinfo, fgl, classes,