restrict, C standard, and gcc version

[Joel Sherrill]

Hi

I accidentally used "restrict" and not "__restrict"
in the devctl.h I added. I will post and commit a
fix for that.

But how I found the issue left me puzzled until
I remembered gcc changed the default C standard
in 5.0. Most of the RTEMS targets are using gcc 6.3
but one is using gcc 4.9. That means that the targets
on gcc 6.3 happily took restrict while the one on
4.9.0 did not.

Just wanted to point this out since it is a very
easy mistake to make.

--joel