gfx: change VSYNC from 60fps to 30fps

parse fps divider from gfx.fps_divider
add one more DisplayConfig with 1/2 refresh rate
report vsync event every 16ms*fps_divider for physical
display and use RefreshPeriod*fps_divider for virtual
display

Change-Id: I580fca6b84a5a199e476c698f3d742b68e59349c
Tracked-On: https://jira01.devtools.intel.com/browse/AW-192
Signed-off-by: wentaoli <[email protected]>
8 files changed
tree: 663f4cc31c3332aa5f8d97e9aa98299b77a11266
  1. merrifield/
  2. moorefield_hdmi/