Added GPIO is "Power Alert". It's uncertain if this
GPIO is set on GPU initialization or only if a change is detected by the
GPU at runtime.
This GPIO can be found on Tesla and sometimes on Fermi GPUs.
Untested, wrote according to documentation.
Signed-off-by: Mark Menzynski <mmenzyns@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>