Fix various compiler warnings on ppc4xx builds (ELDK 4.0)

Patch by Stefan Roese, 18 Jan 2006
diff --git a/board/esd/common/auto_update.c b/board/esd/common/auto_update.c
index d48e972..1decc0e 100644
--- a/board/esd/common/auto_update.c
+++ b/board/esd/common/auto_update.c
@@ -283,7 +283,7 @@
 		 */
 		if (au_image[i].type != AU_NAND) {
 			debug ("flash_write(%p, %lx %x)\n", addr, start, nbytes);
-			rc = flash_write((uchar *)addr, start, nbytes);
+			rc = flash_write((char *)addr, start, nbytes);
 		} else {
 #if (CONFIG_COMMANDS & CFG_CMD_NAND)
 			debug ("nand_rw(%p, %lx %x)\n", addr, start, nbytes);