octeontx2-af: forward error correction configuration

CGX block supports forward error correction modes baseR
and RS. This patch adds support to set encoding mode
and to read corrected/uncorrected block counters

Adds new mailbox handlers set_fec to configure encoding modes
and fec_stats to read counters and also increase mbox timeout
to accomdate firmware command response timeout.

Along with new CGX_CMD_SET_FEC command add other commands to
sync with kernel enum list with firmware.

Signed-off-by: Christina Jacob <cjacob@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>