CorebootPayloadPkg: Use correct BytesPerScanLine

CorebootPayloadPkg: Use correct BytesPerScanLine

Fetch BytesPerScanLine from coreboot table to reflect how the actual
framebuffer is set up instead of guessing it from the horizontal
resolution.

This fixes a garbled display when HorizontalResolution * (BitsPerPixel
/ 8) and pFbInfo->BytesPerScanLine don't match.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Benjamin You <benjamin.you@intel.com>