tps6507x.txt: Remove executable permission

Documention text files shouldn't be executable.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/mfd/tps6507x.txt b/Documentation/devicetree/bindings/mfd/tps6507x.txt
old mode 100755
new mode 100644