octeontx2-af: Support variable number of lmacs

Most of the code in CGX/RPM driver assumes that max lmacs per
given MAC as always, 4 and the number of MAC blocks also as 4.
With this assumption, the max number of interfaces supported is
hardcoded to 16. This creates a problem as next gen CN10KB silicon
MAC supports 8 lmacs per MAC block.

This patch solves the problem by using "max lmac per MAC block"
value from constant csrs and uses cgx_cnt_max value which is
populated based number of MAC blocks supported by silicon.

Signed-off-by: Rakesh Babu Saladi <rsaladi2@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>