MFC r314579,r314785:

r314579 (by np):

Add cxgbetool(8) to the base system.

Move cxgbetool from tools/tools to usr.sbin. Compile and install it on
platforms where cxgbe(4) is built by default. Knobs (WITH_CXGBETOOL and
WITHOUT_CXGBETOOL) have been added so that the user can override the
default setting.

r314785:

Fix some trivial manlint warnings

Sentences should begin on new lines, per manlint.

Bump .Dd for the change

Add cxgbetool(8) to the base system.

Move cxgbetool from tools/tools to usr.sbin. Compile and install it on
platforms where cxgbe(4) is built by default. Knobs (WITH_CXGBETOOL and
WITHOUT_CXGBETOOL) have been added so that the user can override the
default setting.

Reviewed by: ngie@, gnn@, bdrewery@
MFC after: 1 month
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D9854

Add a manual page for cxgbetool. It is incomplete but definitely
better than nothing.

MFC after: 1 month

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

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

Submitted by: gnn

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