This patch adds 'ping_all_vfs' callback that supports pf send message to
all vfs and 'ping_pf' callback that supports vf send message to pf. After
receiving the interrupt, the communication destination gets the message
by sending mailbox.
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>