misc: introduce new mos6522 VIA device and enable it for ppc builds

The MOS6522 VIA forms the bridge part of several Mac devices, including the
Mac via-cuda and via-pmu devices. Introduce a standard mos6522 device that
can be shared amongst multiple implementations.

This is effectively taking the 6522 parts out of cuda.c and turning them
into a separate device whilst also applying some style tidy-ups and including
a conversion to trace-events.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

default-configs/ppc-softmmu.mak

@@ -30,6 +30,7 @@ CONFIG_MAC=y
 CONFIG_ESCC=y
 CONFIG_MACIO=y
 CONFIG_SUNGEM=y
+CONFIG_MOS6522=y
 CONFIG_CUDA=y
 CONFIG_ADB=y
 CONFIG_MAC_NVRAM=y

hw/misc/Makefile.objs

@@ -17,6 +17,9 @@ common-obj-$(CONFIG_INTEGRATOR_DEBUG) += arm_integrator_debug.o
 common-obj-$(CONFIG_A9SCU) += a9scu.o
 common-obj-$(CONFIG_ARM11SCU) += arm11scu.o
 
+# Mac devices
+common-obj-$(CONFIG_MOS6522) += mos6522.o
+
 # PKUnity SoC devices
 common-obj-$(CONFIG_PUV3) += puv3_pm.o