devicetree: property-units: Add uWh and uAh units

Add entries for microwatt-hours and microamp-hours.

Cc: Rob Herring <robh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Liam Breck <kernel@networkimprov.net>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

Documentation/devicetree/bindings/property-units.txt

@@ -25,8 +25,10 @@ Distance
 Electricity
 ----------------------------------------
 -microamp	: micro amps
+-microamp-hours : micro amp-hours
 -ohms		: Ohms
 -micro-ohms	: micro Ohms
+-microwatt-hours: micro Watt-hours
 -microvolt	: micro volts
 
 Temperature