[U-Boot] [PATCH 20/53] binman: Allow state functions to fail to return data

[sjg at google.com]

At present these state functions raise an exception if they cannot find
what is requested. But in some cases the information is optional (e.g. an
fdtmap in a coming patch) so it is better to return gracefully.

Update these two functions to return None when the data cannot be found.

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

 tools/binman/state.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Applied to u-boot-dm, thanks!