staging: r8188eu: remove header file rtw_ioctl_rtl.h

All functions declared in rtw_ioctl_rtl.h are not implemented.
Remove rtw_ioctl_rtl.h and its includes.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210903093354.12645-2-straube.linux@gmail.com


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