staging: r8188eu: remove empty functions

Remove the following empty functions.

Hal_InitChannelPlan()
Hal_CustomizeByCustomerID_8188EU()
_InitBeaconMaxError()

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210906190223.11396-7-straube.linux@gmail.com


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