[AGPGART] uninorth-agp warning fixes

drivers/char/agp/uninorth-agp.c: In function `agp_uninorth_suspend':
drivers/char/agp/uninorth-agp.c:332: warning: cast to pointer from integer of different size
drivers/char/agp/uninorth-agp.c: In function `agp_uninorth_resume':
drivers/char/agp/uninorth-agp.c:354: warning: cast from pointer to integer of different size

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>