crypto: hisilicon/sec - add fallback tfm supporting for XTS mode

Add fallback tfm supporting for hisi_sec driver. Due to the hardware
not supports 192bit key length when using XTS mode. So the driver needs
to setting the soft fallback skcipher tfm for user.

Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>