staging: wilc1000: remove host_int_set_RSNAConfigPSKPassPhrase

This patch removes host_int_set_RSNAConfigPSKPassPhrase function
definition and declaration that is defined at host_interface.c and
host_interface.h. This function is defined but not used anywhere in this
driver so just remove it.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>