binman: Update state when replacing device-tree entries

Since the state module holds references to all the device trees used by
binman, it must be updated when the device trees are updated. Add support
for this.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/state.py

@@ -108,6 +108,22 @@ def GetFdtContents(etype='u-boot-dtb'):
         data = tools.ReadFile(pathname)
     return pathname, data
 
+def UpdateFdtContents(etype, data):
+    """Update the contents of a particular device tree
+
+    The device tree is updated and written back to its file. This affects what
+    is returned from future called to GetFdtContents(), etc.
+
+    Args:
+        etype: Entry type (e.g. 'u-boot-dtb')
+        data: Data to replace the DTB with
+    """
+    dtb, fname, entry = output_fdt_info[etype]
+    dtb_fname = dtb.GetFilename()
+    tools.WriteFile(dtb_fname, data)
+    dtb = fdt.FdtScan(dtb_fname)
+    output_fdt_info[etype] = [dtb, fname, entry]
+
 def SetEntryArgs(args):
     """Set the value of the entry args