media: sony-cxd2880: add optional vcc regulator to bindings

This patchset adds an optional VCC regulator to the bindings of the Sony
CXD2880 DVB-T2/T tuner + demodulator adapter.

Signed-off-by: Neil Armstrong <[e-mail]>
Acked-by: Yasunari Takiguchi <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Sean Young <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Documentation/devicetree/bindings/media/spi/sony-cxd2880.txt

···
 - reg: SPI chip select number for the device.
 - spi-max-frequency: Maximum bus speed, should be set to <55000000> (55MHz).
 
+Optional properties:
+- vcc-supply: Optional phandle to the vcc regulator to power the adapter,
+  as described in the file ../regulator/regulator.txt
+
 Example:
 
 cxd2880@0 {