CVE-2021-47286

In the Linux kernel, the following vulnerability has been resolved: bus:
mhi: core: Validate channel ID when processing command completions MHI
reads the channel ID from the event ring element sent by the device which
can be any value between 0 and 255. In order to prevent any out of bound
accesses, add a check against the maximum number of channels supported by
the controller and those channels not configured yet so as to skip
processing of that event ring element.