tx3912fb: fix improper assignment of info->pseudo_palette

There is no variable pseudo_palette.  Instead, there is u32 cfb8[16]. Use
this for info->pseudo_palette.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>