Mostly all bcma based devices have a PMU and the PMU watchdog should be
used and not the old one in chip common. This patch also calculates the
maximal number the watchdog could be set to.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>