bootm: refactor ramdisk locating code

Move determing if we have a ramdisk and where its located into the
common code. Keep track of the ramdisk start and end in the
bootm_headers_t image struct.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/lib_m68k/bootm.c b/lib_m68k/bootm.c
index fe658fe..241721d 100644
--- a/lib_m68k/bootm.c
+++ b/lib_m68k/bootm.c
@@ -50,7 +50,7 @@
 {
 	ulong sp;
 
-	ulong rd_data_start, rd_data_end, rd_len;
+	ulong rd_len;
 	ulong initrd_start, initrd_end;
 	int ret;
 
@@ -95,14 +95,8 @@
 
 	kernel = (void (*)(bd_t *, ulong, ulong, ulong, ulong))images->ep;
 
-	/* find ramdisk */
-	ret = boot_get_ramdisk (argc, argv, images, IH_ARCH_M68K,
-			&rd_data_start, &rd_data_end);
-	if (ret)
-		goto error;
-
-	rd_len = rd_data_end - rd_data_start;
-	ret = boot_ramdisk_high (lmb, rd_data_start, rd_len,
+	rd_len = images->rd_end - images->rd_start;
+	ret = boot_ramdisk_high (lmb, images->rd_start, rd_len,
 			&initrd_start, &initrd_end);
 	if (ret)
 		goto error;