crypto/virtio: fix global variable multiple definitions
'virtio_hw_internal' global variable is defined in both 'crypto/virtio'
and 'net/virtio' PMDs. This means they share same storage when
application linked with static DPDK library, which is not the intention.
Fixing by adding 'crypto_' prefix to the 'crypto/virtio' driver.
Issue has been detected by '-fno-common' gcc flag.