crypto: octeontx2 - Fix cptvf driver cleanup

This patch fixes following cleanup issues:
 - Missing instruction queue free on cleanup. This
   will lead to memory leak.
 - lfs->lfs_num is set to zero before cleanup, which
   will lead to improper cleanup.

Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>