bindings: nvmem/zii: Fix location of nvmem.txt

The location pointed there is missing "bindings/" on its path.
Acked-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NJonathan Corbet <corbet@lwn.net>

Documentation/devicetree/bindings/nvmem/zii,rave-sp-eeprom.txt

@@ -18,7 +18,7 @@ Optional properties:
 Data cells:
 
 Data cells are child nodes of eerpom node, bindings for which are
-documented in Documentation/bindings/nvmem/nvmem.txt
+documented in Documentation/devicetree/bindings/nvmem/nvmem.txt
 
 Example: