staging: r8188eu: remove ODM_SingleDualAntennaDetection()

Function ODM_SingleDualAntennaDetection() is not used, remove it.
It is the only user of odm_PHY_SaveAFERegisters() and
odm_PHY_ReloadAFERegisters() so remove these functions as well.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210918211046.6865-1-straube.linux@gmail.com


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