msm: adsprpc: Handle ramdump collection

Process exit and ramdump collection synchronization
done using work.

Change-Id: Ib1f30b26537417f9c69fc9510ae34b2c33502e2d
Acked-by: Krishnaiah Tadakamalla <ktadakam@qti.qualcomm.com>
Signed-off-by: Jeya R <jeyr@codeaurora.org>