libpagemap: Add APIs to mark and read idle pages of a process.

pm_kernel_init_page_idle()   - Initialize idle page tracking.
pm_kernel_has_page_idle()    -  Returns 1 if idle page tracking has been
                               successfully initialized.
pm_kernel_get_page_idle()    - Gets the idle status of the page frame.
pm_kernel_mark_page_idle()   - Marks one or many page frames idle.
pm_kernel_page_is_accessed() - Returns 1 if page is accessed.

pm_map_mark_idle()           - Marks mapped pages from a pagemap idle.

Added '-i' usage flag to procmem that tells procmem to use idle page
tracking. The flag is ignored in the absense of '-w' or '-W' options.

Bug: 111694435
Test: procmem -i -h 1
Test: procmem -h -W 1 && procmem -h -w 1
Test: procmem -h -i -W 1 && procmem -h -i -w 1

Change-Id: Ib9cb679427798426c9477500552e9aa83a40fd48
Signed-off-by: Sandeep Patil <sspatil@google.com>
5 files changed