crypto/scheduler: fix uninitialized capabilities

crypto/scheduler: fix uninitialized capabilities

Capability information is updated as slaves are attached,
but if this information is requested via rte_cryptodev_info_get()
when no slaves have been attached, the structure would not be
initialized, leading to a potential segmentation fault.

Therefore, the structure should be initialized with no
capabilities at device creation.

Fixes: 31439ee72b2c ("crypto/scheduler: add API implementations")
Cc: stable@dpdk.org
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Fan Zhang <roy.fan.zhang@intel.com>