soc: qcom: pil: track secure pages used by pil

PIL secures pages are using direct scm call, mark these pages using a magic
flag so that it can be easily identified.

add one check for removing carve out pages, that's already excluded.

Change-Id: If75ab6b4537323e7202c1dd52e2e6677cb61e437
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>