msm: mpq8064: Change in how vcap req_buf calcs num buf

A design change in how req_buf is suppose to work. Before req_buf
would set the number of buffers needed to the minimum required by
VCAP plus one buffer for cycling. The design now is now designed
that req_buf now adds the minimum number of buffers requred by the
VCAP to the value passed in.

Change-Id: If3ac47fee076aefc9095804abfb38cf26c4a806f
Signed-off-by: Terence Hampson <thampson@codeaurora.org>