VGA_MAP_MEM translates to ioremap() on some architectures.  It makes sense
to do this to vga_vram_base, because we're going to access memory between
vga_vram_base and vga_vram_end.

But it doesn't really make sense to map starting at vga_vram_end, because
we aren't going to access memory starting there.  On ia64, which always has
to be different, ioremapping vga_vram_end gives you something completely
incompatible with ioremapped vga_vram_start, so vga_vram_size ends up being
nonsense.

As a bonus, we often know the size up front, so we can use ioremap()
correctly, rather than giving it a zero size.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>