staging: r8188: remove unused power transitions

The r8188 driver defines a number of transitions between different
power states. Remove the transitions which are not used by the rest
of the code.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211219183926.4746-2-martin@kaiser.cx


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