Revert "Revert "scripts: devicetree: Handle mixed case node names""

Yes, revert the revert, was a little too quick to apply this.  The fix
is to cleanup the dtsi file in question.

This reverts commit 67026869.

Change-Id: I933fad9d96ec6375eda33f0b012349f1c39e261f
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>