msm: adsprpc: Handle UAF in process shell memory

BugLink: https://bugs.launchpad.net/bugs/1945470



Added flag to indicate memory used
in process initialization. And, this memory
would not removed in internal unmap to avoid
UAF or double free.

Change-Id: I99e8e4f94644c5d47b4863f89b308bd5de49c1d7
Acked-by: Krishnaiah Tadakamalla <ktadakam@qti.qualcomm.com>
Signed-off-by: Jeya R <jeyr@codeaurora.org>
(cherry picked from commit 4620c916a4d156fc2e17fed3725fc419a9a9e6c0)
Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>