clk: mvebu: cp110: do not depend anymore of the *-clock-output-names

Using the *-clock-output-names property was a convenient way to have a
unique name for each clock even when there are multiple cp110 blocks
as we can find on Armada 8K.

However it has some drawbacks: the main one being a stronger link than
necessary between the driver and the device tree. For example the clock
name can't be changed, removed or moved. It is still the early stage of
introduction of the Armada 7K/8K and the hardware is still not totally
documented, especially for the clock part. By removing the use of
*-clock-output-names it will be easier to add new clocks without breaking
the compatibility.

The name of each clock is now created by using its physical address as a
prefix (as it was done for the platform device names). Thanks to this we
have an automatic way to compute a unique name.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>