dm: avoid dev->req_seq overflow

Since dev->req_seq value is initialized from "reg" property of fdt node,
there is posibility, that address value contained in fdt is greater than
INT_MAX, and then value in dev->req_seq is negative which led to probe()
fail.

This patch fix this problem by ensuring that req_seq is positive, unless
it's one of errno codes.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/device.c b/drivers/core/device.c
index ef41a9b..32e80e8 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -109,6 +109,8 @@
 	dev->seq = -1;
 #ifdef CONFIG_OF_CONTROL
 	dev->req_seq = fdtdec_get_int(gd->fdt_blob, of_offset, "reg", -1);
+	if (!IS_ERR_VALUE(dev->req_seq))
+		dev->req_seq &= INT_MAX;
 	if (uc->uc_drv->name && of_offset != -1) {
 		fdtdec_get_alias_seq(gd->fdt_blob, uc->uc_drv->name, of_offset,
 				     &dev->req_seq);