msm: msm_bus: Account for multiple channels in clock frequency

Currently, for multiple channels on a bus or memory, the aggregated
ab value is divided by the number of channels while calculating
bandwidth values for NoCs. However, the channels are not accounted
for while calculating the clock frequency. This factors
into the calculations only when sum of all ab values exceeds the
max of ib values. In that case, we risk running the clocks higher
than required. This patch fixes the issue.

Change-Id: Ia2ddb5f3bfa6049bcffc909c3b79e6382525129c
Signed-off-by: Gagan Mac <gmac@codeaurora.org>