dt-bindings: mfd: x-powers,axp152: Document AXP323

dt-bindings: mfd: x-powers,axp152: Document AXP323

The X-Powers AXP323 is a PMIC used on some newer Allwinner devices.
It is almost the same as the AXP313, but supports dual-phasing the first
two DC/DC converters. A pure AXP313 driver wouldn't know about this, and
might turn the linked DCDC2 regulator off, as it does not seem to be
used. This makes the AXP323 incompatible to the AXP313a.

Add the new compatible string, and treat it like the AXP313a.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241007001408.27249-2-andre.przywara@arm.com
Signed-off-by: Lee Jones <lee@kernel.org>