lua loader: Add disable-device to disable a device.

disable-device fooX will set hint.foo.X.disabled=1 as a way to easily
disable a device attaching during boot.

Reviewed by:		tsoome
Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D31297

stand/lua/cli.lua

@@ -240,6 +240,21 @@ cli["show-module-options"] = function()
 	pager.close()
 end
 
+cli["disable-device"] = function(...)
+	local _, argv = cli.arguments(...)
+	local d, u
+
+	if #argv == 0 then
+		print("usage error: disable-device device")
+		return
+	end
+
+	d, u = string.match(argv[1], "(%w*%a)(%d+)")
+	if d ~= nil then
+		loader.setenv("hint." .. d .. "." .. u .. ".disabled", "1")
+	end
+end
+
 -- Used for splitting cli varargs into cmd_name and the rest of argv
 function cli.arguments(...)
 	local argv = {...}

stand/lua/cli.lua.8

@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 17, 2020
+.Dd July 24, 2021
 .Dt CLI.LUA 8
 .Os
 .Sh NAME
@@ -91,10 +91,12 @@ module provides the following default commands:
 .It
 .Ic reload-conf
 .It
-.Ic enable-module
+.Ic device-disable
 .It
 .Ic disable-module
 .It
+.Ic enable-module
+.It
 .Ic toggle-module
 .It
 .Ic show-module-options
@@ -131,6 +133,10 @@ The
 .Ic show-module-options
 command will dump the list of modules that loader has been made aware of and
 any applicable options using paged output.
+.Pp
+The
+.Ic device-disable
+command sets the environment variable that disables the device argument.
 .Ss Exported Functions
 The following functions are exported from
 .Nm :