staging: wilc1000: wilc_wfi_cfgoperations.c : remove unused functions

This patch removes unused functions from the wilc_wfi_cfgoperations.c.
 - WILC_WFI_dump_survey
 - WILC_WFI_auth
 - WILC_WFI_assoc
 - WILC_WFI_deauth
 - WILC_WFI_disassoc
 - WILC_WFI_set_bitrate_mask

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>