6ed8303443
- Detach the gpiobus and the gpioc devices from the GPIO controller. - Fix the leak of gpiobus IRQ rman(9) region descriptor. - Fix the leak of child ivars and IRQ resource list. While here return NULL (instead of 0) for a device_t that fails to allocate the ivar memory. Tested with gpiobus built as a module. Sponsored by: Rubicon Communications (Netgate)