staging: r8188eu: remove HW_VAR_DM_FUNC_RESET from SetHwReg8188EU()

Remove the HW_VAR_DM_FUNC_RESET case from SetHwReg8188EU() and move
its functionality to a static function. This is part of the ongoing
effort to get rid of SetHwReg8188EU().

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220709094458.9578-5-straube.linux@gmail.com


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