dt-bindings: marvell,mmp2: fix typos in bindings doc

A pair of rather trivial ones.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/clock/marvell,mmp2.txt

@@ -18,4 +18,4 @@ Required Properties:
 Each clock is assigned an identifier and client nodes use this identifier
 to specify the clock which they consume.
 
-All these identifier could be found in <dt-bindings/clock/marvell-mmp2.h>.
+All these identifiers could be found in <dt-bindings/clock/marvell,mmp2.h>.