o Introduce PUC_PORT_TYPE_UART so that we can attach to uart(4),
o Introduce port sub-types (eg PUC_PORT_UART_NS8250, PUC_PORT_UART_Z8530)
to handle different hardware and determine resource sizes.
o Introduce two new IVARs: PUC_IVAR_SUBTYPE and PUC_IVAR_REGSHFT. Both
are used by uart(4) to get sufficient information to talk to the HW.
o Introduce PUC_FLAGS_ALTRES to tell puc(4) to try memory mapped I/O
if I/O port space cannot be allocated, or vice versa.
o Have ports of type PUC_PORT_TYPE_COM attach to uart(1) if attaching
to sio(4) fails (due to not having the sio driver).
o Put struct puc_device_description in struct puc_softc instead of
having a pointer to a device description in the softc. This allows
us to create device descriptions on the fly without having to use
malloc() or otherwise have them staticly defined.
o Move puc_find_description() from puc.c to puc_pci.c as it's specific
to PCI.
o Add EBUS and SBUS frontends for use on sparc64. Note that the P in
puc stands for PCI, so we kinda mess things up here. It's too soon
to worry about it though. We'll know what to do about it in time.
NOTE: This commit changes the behaviour of puc(4) to not quieten the
device probe and attach for child devices. The uart(4) driver provides
additional device description that is valuable to have.