[PATCH] visws: sgivwfb as module needs exports

With CONFIG_FB_SGIVW=m:
WARNING: "sgivwfb_mem_size" [drivers/video/sgivwfb.ko] undefined!
WARNING: "sgivwfb_mem_phys" [drivers/video/sgivwfb.ko] undefined!

(or don't allow FB_SGIVW=m in Kconfig)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>