octeontx2-af: Clear NPC MCAM entries before update

Writing into NPC MCAM1 and MCAM0 registers are suppressed if
they happened to form a reserved combination. Hence
clear and disable MCAM entries before update.

For HRM:
[CAM(1)]<n>=1, [CAM(0)]<n>=1: Reserved.
The reserved combination is not allowed. Hardware suppresses any
write to CAM(0) or CAM(1) that would result in the reserved combination for
any CAM bit.

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