crypto: chelsio - Move DMA un/mapping to chcr from lld cxgb4 driver

Allow chcr to do DMA mapping/Unmapping instead of lld cxgb4.
It moves "Copy AAD to dst buffer" requirement from driver to
firmware.

Signed-off-by: Harsh Jain <harsh@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>