octeontx2-af: cn10k: Add RPM LMAC pause frame support

Flow control configuration is different for CGX(Octeontx2)
and RPM(CN10K) functional blocks. This patch adds the necessary
changes for RPM to support 802.3 pause frames configuration on
cn10k platforms.

Signed-off-by: Rakesh Babu <rsaladi2@marvell.com>
Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <Sunil.Goutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>