libhwc2.1: Add function to set frame rate for performance info

This patch adds function to set frame rate for calculating performace.
Frame rate to calculate performance information can be changed.

Change-Id: Ibcbff5eb5faa938151f0badd6571f5fe960753e2
Signed-off-by: HyunKyung Kim <hk310.kim@samsung.com>
2 files changed