BOOT: Add RAW ramdisk support to bootz

This patch allows loading RAW ramdisk via bootz command. The raw ramdisk is
loaded only in case it's size is specified:

  bootz <kernel addr> <ramdisk addr>:<ramdisk size> <fdt addr>

For example:

  bootz 0x42000000 0x43000000:0x12345 0x44000000

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Tom Warren <TWarren@nvidia.com>
Cc: albert.u.boot@aribaud.net
Cc: afleming@gmail.com
Cc: Simon Glass <sjg@chromium.org>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
diff --git a/common/image.c b/common/image.c
index 8c644b7..103e0e6 100644
--- a/common/image.c
+++ b/common/image.c
@@ -797,6 +797,7 @@
 	ulong rd_addr, rd_load;
 	ulong rd_data, rd_len;
 	const image_header_t *rd_hdr;
+	char *end;
 #if defined(CONFIG_FIT)
 	void		*fit_hdr;
 	const char	*fit_uname_config = NULL;
@@ -994,9 +995,17 @@
 			break;
 #endif
 		default:
-			puts("Wrong Ramdisk Image Format\n");
-			rd_data = rd_len = rd_load = 0;
-			return 1;
+#ifdef CONFIG_SUPPORT_RAW_INITRD
+			if (argc >= 3 && (end = strchr(argv[2], ':'))) {
+				rd_len = simple_strtoul(++end, NULL, 16);
+				rd_data = rd_addr;
+			} else
+#endif
+			{
+				puts("Wrong Ramdisk Image Format\n");
+				rd_data = rd_len = rd_load = 0;
+				return 1;
+			}
 		}
 	} else if (images->legacy_hdr_valid &&
 			image_check_type(&images->legacy_hdr_os_copy,