Add an option for using smaps_rollup

Add an option for using smaps_rollup

Recent Linux kernel provides an entry in procfs, namely smaps_rollup,
to improve performance of user programs which want to get the statistics
of process memory like memps.

This patch add an option for using smaps_rollup. If the target kernel
does not provide smaps_rollup, memps falls back to default lookup path
which traverses the smaps file of the process.

Change-Id: I377e00f5eb92f5ba97c583329198f39741e6b2d2
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>