The search logic in the gpio demux walks all possible gpio blocks starting
at the specified pin.  The trouble on bf537 parts when we demux the port
F and port G mask A interrupts is that we also demux port H mask A ints.
Most of the time this isn't an issue as people don't usually use port H,
but might as well avoid it when possible.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>