usb: dwc3: haps: Constify the software node

usb: dwc3: haps: Constify the software node

What platform_device_add_properties() does is it allocates
dynamically a software node that will contain the device
properties supplied to it, and then couples that node with
the device. Since that node is always created, it might as
well be constant.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210204141711.53775-4-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>