The IMG PDC watchdog probe function calls pdc_wdt_stop() prior to
watchdog_set_drvdata(), causing a NULL pointer dereference when
pdc_wdt_stop() retrieves the struct pdc_wdt_dev pointer using
watchdog_get_drvdata() and reads the register base address through it.
Fix by moving the watchdog_set_drvdata() call earlier, to where various
other pdc_wdt->wdt_dev fields are initialised.