firmware: vpd: Tie firmware kobject to device lifetime

firmware: vpd: Tie firmware kobject to device lifetime

commit e4b28b3c3a405b251fa25db58abe1512814a680a upstream.

It doesn't make sense to have /sys/firmware/vpd if the device is not
instantiated, so tie its lifetime to the device.

Fixes: 049a59db34eb ("firmware: Google VPD sysfs driver")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>