regulator: bd9576: fix regulator binfdings dt node names

Add regulator- prefix to allowed regulator node names. Prefix is expected
by the driver and the actual binding yaml description.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/3d92de2085f0c074929861a2f791bf4070920e83.1601885841.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: M-Vaittinen

Documentation/devicetree/bindings/regulator/rohm,bd9576-regulator.yaml

@@ -17,7 +17,8 @@ description: |
   on the device tree.
 
   The valid names for BD9576 regulator nodes are
-  vd50, vd18, vdddr, vd10, voutl1, vouts1
+  regulator-vd50, regulator-vd18, regulator-vdddr, regulator-vd10,
+  regulator-voutl1, regulator-vouts1
 
 patternProperties:
   "regulator-.+":