cryptodev: add user defined name for vdev

cryptodev: add user defined name for vdev

This patch adds a user defined name initializing parameter to cryptodev
library.

Originally, for software cryptodev PMD, the vdev name parameter is
treated as the driver identifier, and will create an unique name for each
device automatically, which is not necessarily as same as the vdev
parameter.

This patch allows the user to either create a unique name for his software
cryptodev, or by default, let the system creates a unique one. This should
help the user managing the created cryptodevs easily.

Examples:
CLI command fragment 1: --vdev "crypto_aesni_gcm_pmd"
The above command will result in creating a AESNI-GCM PMD with name of
"crypto_aesni_gcm_X", where postfix X is the number assigned by the system,
starting from 0. This fragment can be placed in the same CLI command
multiple times, resulting the postfixs incremented by one for each new
device.

CLI command fragment 2: --vdev "crypto_aesni_gcm_pmd,name=gcm1"
The above command will result in creating a AESNI-GCM PMD with name of
"gcm1". This fragment can be placed in the same CLI command multiple
times, as long as each having a unique name value.

Signed-off-by: Fan Zhang <roy.fan.zhang@intel.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>