qcacmn: Always enable AVOID_FREQUENCIES vendor subcmd
Since AVOID_FREQUENCIES vendor subcmd might be needed even when
FEATURE_WLAN_CH_AVOID is disabled, always enable
QCA_NL80211_VENDOR_SUBCMD_AVOID_FREQUENCY_INDEX in the vendor
subcmd list.
Change-Id: I4ac774d16540306fdb1301f9f182eeea8571388b
CRs-Fixed: 2045120