alpr board: Fix GCC 4.6 build warnings

Fix:
fpga.c: In function 'fpga_pre_fn':
fpga.c:88:16: warning: variable 'reg' set but not used
[-Wunused-but-set-variable]
nand.c: In function 'alpr_nand_dev_ready':
nand.c:125:18: warning: variable 'val' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
diff --git a/board/prodrive/alpr/nand.c b/board/prodrive/alpr/nand.c
index b18c96b..d35cfed 100644
--- a/board/prodrive/alpr/nand.c
+++ b/board/prodrive/alpr/nand.c
@@ -122,12 +122,10 @@
 
 static int alpr_nand_dev_ready(struct mtd_info *mtd)
 {
-	volatile u_char val;
-
 	/*
 	 * Blocking read to wait for NAND to be ready
 	 */
-	val = readb(&(alpr_ndfc->addr_wait));
+	(void)readb(&(alpr_ndfc->addr_wait));
 
 	/*
 	 * Return always true