octeontx2-pf: Cleanup flow rule management

Current MCAM allocation scheme allocates a single lot of
MCAM entries for ntuple filters, unicast filters and VF VLAN
rules. This patch attempts to cleanup this logic by segregating
MCAM rule allocation and management for Ntuple rules and unicast,
VF VLAN rules. This segregation will result in reusing most of
the logic for supporting ntuple filters for VF devices.

Also added debug messages for MCAM entry allocation failures.

Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>