ARM: dts: sun6i: a31s: bpi-m2: improve pmic properties

ARM: dts: sun6i: a31s: bpi-m2: improve pmic properties

commit b23af6ad8d2f708c4c3f92dd8f82c233247ba8bf upstream.

The eldoin is supplied from the dcdc1 regulator. The N_VBUSEN pin is
connected to an external power regulator (SY6280AAC).
With this commit we update the pmic binding properties to support
those features.

Fixes: 7daa21370075 ("ARM: dts: sunxi: Add regulators for Sinovoip BPI-M2")
Cc: <stable@vger.kernel.org>
Signed-off-by: Philipp Rossak <embed3d@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>