octeontx2-af: Map NIX block from CGX connection

Firmware configures NIX block mapping for all CGXs
to achieve maximum throughput. This patch reads
the configuration and create mapping between RVU
PF and NIX blocks. And for LBK VFs assign NIX0 for
even numbered VFs and NIX1 for odd numbered VFs.

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Rakesh Babu <rsaladi2@marvell.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>