[PATCH] vga16fb: Convert vga16fb as a platform device

- Convert vga16fb as a platform device

- use framebuffer_alloc() to dynamically allocate resources, and
  framebuffer_release() to free

- remove unneeded casts

- trivial whitespace changes

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>