fbdev: nv: drop useless CONFIG_PCI checks

Both FB_RIVA and FB_NVIDIA depends on PCI, so CONFIG_PCI always defined for
them.

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