PPC: Add dump_mmu() for 6xx

"(qemu) info tlb" is a very useful tool for debugging, so I implemented
the missing 6xx version.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
[agraf: fix printfs on hwaddr to PRI]
Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Fix GDB read on code area for PPC6xx

On PPC 6xx, data and code have separated TLBs. Until now QEMU was only
looking at data TLBs, which is not good when GDB wants to read code.

This patch adds a second call to get_physical_address() with an
ACCESS_CODE type of access when the first call with ACCESS_INT fails.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Introduce an alias cache for faster lookups

When running QEMU with "-cpu ?" we walk through every alias for every
target CPU we know about. This takes several seconds on my very fast
host system.

Let's introduce a class object cache in the alias table. Using that we
don't have to go through the tedious work of finding our target class.
Instead, we can just go directly from the alias name to the target class
pointer.

This patch brings -cpu "?" to reasonable times again.

Before:
  real    0m4.716s

After:
  real    0m0.025s

Signed-off-by: Alexander Graf <agraf@suse.de>

---

It would be even nicer if we could have the alias table parsed during compile
time. Then instead of having

  { string alias, string base_model }

we would simply get

  { string alias, Class *klass }

in the .rodata section.

But I can't really think of a clever way to do this. Especially since we want
to have the ability to have aliases that don't ever match any implemented CPU.
PPC: Add clock-frequency export for Mac machines

Support in fwcfg has been around for exposure of the clock-frequency
CPU property. OpenBIOS reads it, we just never exposed it.

Since Mac OS X is very picky about its clock frequency values, let's
just take a known good value and always expose that.

Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - rename fwcfg var to CLOCKFREQ to better reflect what it means
PPC: g3beige:  Move secondary IDE bus to mac-io

On a real G3 Beige the secondary IDE bus lives on the mac-io chip, not
on some random PCI device. Move it there to become more compatible.

While at it, also clean up the IDE channel connection logic.

Signed-off-by: Alexander Graf <agraf@suse.de>