gralloc: let target configure page flipping ioctl

Let vendor choose which framebuffer ioctl (FBIOPUT_VSCREENINFO or
FBIOPAN_DISPLAY) is best suited to do page-flip on its target platform.
Neither API is well documented about their usage and most of the
time it really depends on the respective framebuffer driver implementation.

* Default ioctl to do page-flip is FBIOPUT_VSCREENINFO.
* Set "TARGET_USE_PAN_DISPLAY=true" in board config file to use FBIOPAN_DISPLAY.

Change-Id: Ic3a50bd0f5fe37ac0149e11649c4abdadea85529
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
2 files changed