intel_poller can be used to poll various display registers
(IIR,scanline/pixel/flip/frame counter, live address, etc.).
It can be used to determine eg. at which scanline or pixel count certain
events occur.
v2: s/intel_poller/intel_display_poller/
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>