tools/intel_display_bandwidth: Tool for measuring display memory bandwidth utilization

Introduce a small tool for measing the display enging
memory bandwidth utilization. Generally this is available
on SNB+, except on TGL/derivatives where the relevant
registers weren't updated to cope with the new ABOX layout
in the hardware.

Quite handy for confirming that FBC/CCS/etc. are doing their
job.

Not 100% sure about the required scaling factor because
bspec claims it's only needed for MTL, but my ADL definitely
needs it already.

v2: Fix long option handling

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>