cmd: ide: Make the first device the default one

At present the IDE device number is initialized to -1, which means
we cannot type "ide read" command before setting the device number
via "ide device #".

For convenience, let's set the first device as the default one.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/ide.c

@@ -30,7 +30,7 @@
 #endif
 
 /* Current I/O Device	*/
-static int curr_device = -1;
+static int curr_device;
 
 int do_ide(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 {