* utils-gen.scm (gen-sfmt-enum-decl): Use @prefix@ and @PREFIX@
instead of @cpu@ and @CPU@ to generically prefix symbol names.
* sim-cpu.scm (-gen-sem-fn-table-entry): Likewise.
(-gen-semantic-fn-table): Likewise.
(-gen-scache-semantic-fn): Likewise.
(-gen-no-scache-semantic-fn): Likewise.
(cgen-read.c): Likewise.
(cgen-sem-switch.c): Likewise.
* desc-cpu.scm (cgen-desc.c): Use @arch@, not @prefix@, since this
is a filename prefix.
* sim-decode.scm (IDESC-TABLE-VAR): Use @prefix@, et al.
(-gen-decode-insn-globals): Likewise.
(-gen-idesc-decls): Likewise.
(cgen-decode.h): Likewise.
(cgen-decode.c): Likewise.
* sim.scm (gen-cpu-insn-enum-decl): Likewise.
(gen-cpu-insn-enum): Likewise.
(sim-finish!): Likewise.