Revert "mmc: add new request stats infrastructure"

This reverts commit 66842b019fba9e31b4232809f95f8cb86b30954d
and parts of commit I05db0959ded400e292eb5e84e1ecfc579b78ee62.

This patch removes the aync_request statistics from the operational
code. This includes counters and functions which modify these counters.
In addition we remove any code that is dependent of these statistics.

Change-Id: Id4b92a242615afc54647b5b6f057f7d7b88175f1
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
6 files changed