regulator: dt bindings: add BD71847 device-tree binding documentation

Add ROHM BD71847 Power Management IC regulator binding information to
device-tree binding documents.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt

-ROHM BD71837 Power Management Integrated Circuit (PMIC) regulator bindings
+ROHM BD71837 and BD71847 Power Management Integrated Circuit regulator bindings
 
 Required properties:
- - regulator-name: should be "buck1", ..., "buck8" and "ldo1", ..., "ldo7"
+ - regulator-name: should be "buck1", ..., "buck8" and "ldo1", ..., "ldo7" for
+                   BD71837. For BD71847 names should be "buck1", ..., "buck6"
+		   and "ldo1", ..., "ldo6"
 
 List of regulators provided by this controller. BD71837 regulators node
 should be sub node of the BD71837 MFD node. See BD71837 MFD bindings at
@@ -16,10 +18,14 @@ disabled by driver at startup. LDO5 and LDO6 are supplied by those and
 if they are disabled at startup the voltage monitoring for LDO5/LDO6 will
 cause PMIC to reset.
 
-The valid names for regulator nodes are:
+The valid names for BD71837 regulator nodes are:
 BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6, BUCK7, BUCK8
 LDO1, LDO2, LDO3, LDO4, LDO5, LDO6, LDO7
 
+The valid names for BD71847 regulator nodes are:
+BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6
+LDO1, LDO2, LDO3, LDO4, LDO5, LDO6
+
 Optional properties:
 - Any optional property defined in bindings/regulator/regulator.txt