firmware_abi.h with structs for OpenBIOS landed in hw/sparc/ by mistake
- move it to hw/nvram/ alongside fw_cfg.h. In addition to sparc it's
included from ppc mac_nvram.c and will need to include it from prep.c in
the future.
Acked-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
