staging: brcm80211: remove static variables from wl_cfg80211.c

The source file contained two static variable which were used by
the driver instance. This makes having multiple instances of the driver
on one system impossible. This patch removes the use of these static
variables allowing multiple driver instances.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>