bmpblk: Allow changing preview window size.

Most x86 platforms are using stretched output images and will be scaled by BIOS.
To help checking if the output images looks fine, bitmap_viewer needs to support
overriding the preview window size and scale when needed.

A new param "panel_size" is now available for the "bitmap_viewer" command, ex:

  ./bitmap_viewer DEFAULT.yaml 1366x768

This will preview bitmaps in a 1366x768 window, and scale the images (by the
first image in screen) if required.

BUG=none
TEST=manual:
  Run.
     make falco; # Saw correct panel size param (1366x768) in output.
     bitmap_viewer build/falco/DEFAULT.yaml 1366x768 # See correct images.

Change-Id: I60a4890d349681c72f02911aaba0d140215cdfe1
Reviewed-on: https://chrome-internal-review.googlesource.com/155466
Tested-by: Hung-Te Lin <[email protected]>
Reviewed-by: Bill Richardson <[email protected]>
Commit-Queue: Hung-Te Lin <[email protected]>
3 files changed