In contrib/binutils/bfd/elf32-ppc.c, avoid warnings about case values
not being in the enumerated type 'enum elf_ppc_reloc_type', by casting
the switch argument to int.

MFC after:	3 days
Remove dev/virtio/virtio.h include from BERI VirtIO

This header file contains prototypes and defines that only make
sense to the guest VirtIO device drivers.

Reviewed by:	br