msm: ADSPRPC: Add start and end timer for map and buffer

Get kernel time during start and end of map create
to keep track of time taken to create map. The time
variables are added as member of map struct. Same
time variables are added for buffers also.

Change-Id: I6454f5b60bec1a24a43ea1b7539ec45ba5358f2e
Acked-by: Ekansh Gupta <ekangupt@qti.qualcomm.com>
Signed-off-by: Jeya R <jeyr@codeaurora.org>