Avoid infinite include loops, especially with bits/wordsize.h which is
now possible with the synthesized headers since we now also synthesize
bits/wordsize.h itelf for some arches e.g. arm/aarch64
In cases where extra preprocessing tools are used such as clang-tidy
e.g. and these tools are not passed the knowledge about architecture
then case comes where we enter into header include loop for
bits/wordsize.h, since this template does explicitly include
bits/wordsize.h
To fix this emits the pragma once at beginning of file, this is better
solution than include guards, and pragma once is practically supported
on all compilers except few e.g. cray c/c++ compiler
Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>