soc: qcom: pil: Add imem cookie for minidump

Add imem cookie for minidump, This will help to
debug minidump faiure cases.

Change-Id: I5e3878cdd6e3bae2e2e400a016fe0e4e24f75281
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
[schikk@codeaurora.org: Resolved merge conflicts]
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>