Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r253870, r258698 (by gnn@), r259048, and r261534.

r253870:
Teach cxgbetool to display T5 congestion manager context.

r258698:
cxgbetool: "modinfo" command to display SFP+ module information.

trantor:~# cxgbetool t5nex0 modinfo 1
ID: SFP
Vendor FINISAR CORP.
SN AJ10JQR
PN FTLX8571D3BCL
Rev A
Temp: +35C
Vcc 3.225600V
TX Bias 2.176000uA
TX Power 0.588800mW
RX Power 0.486400mW

r259048:
Two new cxgbetool subcommands to set up scheduler classes and to bind
them to NIC queues.

r261534:
cxgbetool: Display the congestion channel map in hex.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

cxgbetool: a tool for the cxgbe(4) driver.