ads5121: fix compiler warnings (unused variables)

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/cpu/mpc512x/iopin.c b/cpu/mpc512x/iopin.c
index 01ab34a..3d7042d 100644
--- a/cpu/mpc512x/iopin.c
+++ b/cpu/mpc512x/iopin.c
@@ -27,7 +27,7 @@
 
 void iopin_initialize(iopin_t *ioregs_init, int len)
 {
-	short i, j, n, p;
+	short i, j, p;
 	u_long *reg;
 	immap_t *im = (immap_t *)CFG_IMMR;