staging: r8188: remove interface mask from power transitions

For the r8188 driver, we always have a usb interface. We can remove
the power transition steps that are not applicable for a usb interface.

We can then remove the interface mask itself.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211219183926.4746-6-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>