CHROMIUM: ath10k: Fix the wrong calculation of number of unique BI

The number of unique beacon interval is calculated wrongly
as during ieee80211_open call, interface combination check
with beacon interval equal to zero is called. During ieee80211_start_ap
correct beacon interval is sent to interface combination check.
This leads to considering beacon interval zero as a unique interval.
Also when the beacon interval matches,i.e., when is_unique_bi is set
to zero, the number of unique beacon interval is calculated wrongly.

Fix these issues by ignoring the calculation of unique interval
in case of beacon interval is zero and return bi_idx differently
based on value of is_unique_bi.

BUG=b:132147953
TEST=None

Change-Id: Icc67db22ee5cdb335c9a73c2ccd727458966ed1b
Signed-off-by: Surabhi Vishnoi <svishnoi@codeaurora.org>
Signed-off-by: Vamsi Singamsetty <vamssi@codeaurora.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1597062


Reviewed-by: Zhihong Yu <zhihongyu@chromium.org>
Reviewed-by: Govind Singh <govinds@qualcomm.corp-partner.google.com>
Commit-Queue: Zhihong Yu <zhihongyu@chromium.org>
Tested-by: Zhihong Yu <zhihongyu@chromium.org>