brcmsmac: fix brcms_c_regd_init() which crashed after 11ad patch

This patch fixes an OOPS in brcmsmac driver, which was introduced
by the 11ad patch 'cfg80211: add 802.11ad (60gHz band) support'.
The value IEEE80211_NUM_BANDS increased, which was used in the
brcms_c_regd_init() function.

Cc: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>