fb: amifb: fix build warnings when not builtin

fb: amifb: fix build warnings when not builtin

Fix build warning when built as a loadable module.
amifb_setup() and amifb_setup_mcap() are only needed when the driver
is builtin.
This matches how the functions are called (using #ifndef MODULE).

../drivers/video/fbdev/amifb.c:2344:19: warning: 'amifb_setup' defined but not used [-Wunused-function]
 static int __init amifb_setup(char *options)

../drivers/video/fbdev/amifb.c:2307:20: warning: 'amifb_setup_mcap' defined but not used [-Wunused-function]
 static void __init amifb_setup_mcap(char *spec)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>