cxgbe(4): Very basic T6 awareness. This is part of ongoing work to
update to the latest internal shared code.

• Add a chip_params structure to keep track of hardware constants for all generations of Terminators handled by cxgbe.
• Update t4_hw_pci_read_cfg4 to work with T6.
• Update the hardware debug sysctls (hidden within dev.<tNnex>.<n>.misc.*) to work with T6. Most of the changes are in the decoders for the CIM logic analyzer and the MPS TCAM.
• Acquire the regwin lock around indirect register accesses.

Obtained from: Chelsio Communications
Sponsored by: Chelsio Communications