staging: rtl8188eu: remove unused defines

Some defines in usb_ops_linux.h are not used by the rtl8188eu driver.
Remove them.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210407170531.29356-3-martin@kaiser.cx


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