net: ethernet: ti: cpsw_ale: use regfields for number of Entries and Policers

Use regfields for number of ALE Entries and Policers.

The variants that support Policers/Classifiers have the number
of policers encoded in the ALE_STATUS register.

Use that and show the number of Policers in the ALE info message.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>