cxgb4: Add API to correctly calculate tuple fields

Adds API cxgb4_select_ntuple so as to enable Upper Level Drivers to correctly
calculate the tuple fields.

Adds constant definitions for TP_VLAN_PRI_MAP for the Compressed
Filter Tuple field widths and structures and uses them.

Also, the CPL Parameters field for T5 is 40 bits so we need to prototype
cxgb4_select_ntuple() to calculate and return u64 values.

Based on original work by Casey Leedom <leedom@chelsio.com>

Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>