virtio-msg: add new command for bus normative

Add a new command to have a standard way to define virtio-msg bus
normative statements.

Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>

Author: bertrand-marquis

commands.tex

@@ -7,9 +7,10 @@
 % How we format a field name
 \newcommand{\field}[1]{\emph{#1}}
 
-% Mark a normative section (driver or device)
+% Mark a normative section (driver, device, or bus)
 \newcommand{\drivernormative}[3]{#1{Driver Requirements: #2}\label{drivernormative:#3}}
 \newcommand{\devicenormative}[3]{#1{Device Requirements: #2}\label{devicenormative:#3}}
+\newcommand{\busnormative}[3]{#1{Bus Requirements: #2}\label{busnormative:#3}}
 \newcounter{clausecounter}
 \newcommand{\conformance}[2]{
 	\stepcounter{clausecounter}