Move parallel_hds_isa_init to hw/isa/isa-bus.c

Disabling CONFIG_PARALLEL cause removing parallel_hds_isa_init defined in
parallel.c. This function is called during initialization of some boards so
disabling CONFIG_PARALLEL cause build failure.

This patch moves parallel_hds_isa_init to hw/isa/isa-bus.c so it is included
in case of disabled CONFIG_PARALLEL. Build is successful but qemu will abort
with "Unknown device" error when function is called.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Message-Id: <1431509970-32154-1-git-send-email-mrezanin@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>