[POWERPC] Fix interrupt routing and setup of ULI M1575 on FSL boards

[POWERPC] Fix interrupt routing and setup of ULI M1575 on FSL boards

The interrupt routing in the device trees for the ULI M1575 was
inproperly using the interrupt line field as pci function.  Fixed
up the device tree's to actual conform for to specification and
changed the interrupt mapping code so it just uses a static mapping
setup as follows:

PIRQA - IRQ9
PIRQB - IRQ10
PIRQC - IRQ11
PIRQD - IRQ12
USB 1.1 OCHI (1c.0) - IRQ12
USB 1.1 OCHI (1c.1) - IRQ9
USB 1.1 OCHI (1c.2) - IRQ10
USB 1.1 ECHI (1c.3) - IRQ11
LAN (1b.0) - IRQ6
AC97 (1d.0) - IRQ6
Modem (1d.1) - IRQ6
HD Audio (1d.2) - IRQ6
SATA (1f.1) - IRQ5
SMB (1e.1) - IRQ7
PMU (1e.2) - IRQ7
PATA (1f.0) - IRQ14/15

Took the oppurtunity to refactor the code into a single file so we
don't have to duplicate these fixes on the two current boards in the
tree and several forth coming boards that will also need the code.

Fixed RTC support that requires a dummy memory read on the P2P bridge
to unlock the RTC and setup the default of the RTC alarm registers to
match with a basic x86 style CMOS RTC.

Moved code that poked ISA registers to a FIXUP_FINAL quirk to ensure
the PCI IO space has been setup properly before we start poking ISA
registers at random locations.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>