- Import cmdcnst.h and vga.h headers from the 'vga_new' VGA Miniport Driver,
that contain definitions related to VGA registers as well as command-stream
functionality.
- Replace a bunch of hardcoded values by their corresponding defintions.
- Replace "Captain-Obvious" comments in VgaIsPresent() with actual
explanations from the corresponding function in 'vga_new'.
- Simplify the VgaInterpretCmdStream() function, based on the
corresponding one from 'vga_new'.
- Use concise comments in the 'AT_Initialization' command stream definition.
- Import the 'VGA_640x480' initialization command stream from 'vga_new'
and use it as the full VGA initialization stream whenever the HAL
does not handle the VGA display (HalResetDisplay() returning FALSE).
Otherwise we just use the 'AT_Initialization' command stream that
performs minimal initialization.
- Remove unused AT_Initialization and other declarations from ARM build.
