staging: rtl8188eu: remove unused enum and defines

IQK_BB_REG_NUM_MAX, RTL8711_RF_MAX_SENS, RTL8711_RF_DEF_SENS,
NUM_REGULATORYS and enum _RTL8712_RF_MIMO_CONFIG_ are not used
in the driver code, remove them.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200118173343.32405-3-straube.linux@gmail.com


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