fbdev: framebuffer_alloc() fixes

Correct the dev arg of framebuffer_alloc() in arkfb, s3fb and vt8623fb.

Signed-off-by: Ondrej Zajicek <santiago@crfreenet.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>