ppc: Convert PPC UIC to a QOM device

ppc: Convert PPC UIC to a QOM device

Currently the PPC UIC ("Universal Interrupt Controller") is implemented
as a non-QOM device in ppc4xx_devs.c. Convert it to a proper QOM device
in hw/intc.

The ppcuic_init() function is retained for the moment with its current
interface; in subsequent commits this will be tidied up to avoid the
allocation of an irq array.

This conversion adds VMState support.

It leaves the LOG_UIC() macro as-is to maximise the extent to which
this is simply code-movement rather than a rewrite (in new code it
would be better to use tracepoints).

The default property values for dcr-base and use-vectors are set to
match those use by most of our boards with a UIC.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20201212001537.24520-3-peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>