net/bnxt: fix setting forced speed

net/bnxt: fix setting forced speed

The "active_fec_signal_mode" in HWRM_PORT_PHY_QCFG response
does not return correct value till the link is up. Driver cannot
rely on active_fec_signal_mode while setting forced speed.

While setting forced speed of 50G/100G/200G, check if PAM4 speeds
are supported for the port first and then populate the HWRM request
accordingly.

Also, If PAM4 speed is supported, use PAM4 supported speed while
reporting speed capabilities.

Fixes: c23f9ded0391 ("net/bnxt: support 200G PAM4 link")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>