hwdep: device-info: allow to set property at instantiation

hwdep: device-info: allow to set property at instantiation

ALSAHwdep.DeviceCommon interface allows subclass to implement
get_device_info() virtual function. In the function, DeviceInfo should
be instantiated with correct properties for device information. However,
current implementation of DeviceInfo doesn't have setter function for
the properties.

This commit adds setter function for the purpose. It's allowed to set
them at construction only.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>