Timer 12 is not necessarily available on non-GP devices (see e.g.
http://marc.info/?l=linux-omap&m=129433066521102&w=2), so it should be
registered only on GP OMAPs. With this change it's again possible to
boot RM-680 into the shell. Tested with 3.2-rc4.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
[paul@pwsan.com: changed subject line] Signed-off-by: Paul Walmsley <paul@pwsan.com>