staging: wilc1000: host_interface: removes unused functions

This patch removes unused functions at host_interface files.
 - host_int_send_join_leave_info_to_host
 - host_int_send_network_info_to_host

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>