If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.
Export the module alias information using the MODULE_DEVICE_TABLE() macro.
Before this patch:
$ modinfo drivers/watchdog/bcm7038_wdt.ko | grep alias
$
After this patch:
$ modinfo drivers/watchdog/bcm7038_wdt.ko | grep alias
alias: of:N*T*Cbrcm,bcm7038-wdtC*
alias: of:N*T*Cbrcm,bcm7038-wdt