uboot-imx

binman: Allow zero-size sections

At present if there is only a zero-size entry in a section this is
reported as an error, e.g.:

   Offset 0x0 (0) is outside the section starting at 0x0 (0)

Adjust the logic in CheckEntries() to avoid this.

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