In order to not clutter the include/linux directory with SoC specific
headers, move the Tegra-specific headers out into a separate directory.

Signed-off-by: Thierry Reding <treding@nvidia.com>

While poking at something using the for-3.12/* trees, I hit the
following compile error:
drivers/built-in.o: In function `tegra_pcie_map_irq':
/builddir/build/BUILD/kernel-3.10.fc20/linux-3.11.0-0.rc6.git4.1.fc20.armv7hl/drivers/pci/host/pci-tegra.c:640:
undefined reference to `tegra_cpuidle_pcie_irqs_in_use'
drivers/built-in.o: In function `tegra_msi_map':
/builddir/build/BUILD/kernel-3.10.fc20/linux-3.11.0-0.rc6.git4.1.fc20.armv7hl/drivers/pci/host/pci-tegra.c:1227:
undefined reference to `tegra_cpuidle_pcie_irqs_in_use'
make: *** [vmlinux] Error 1

Since our .config had CONFIG_CPU_IDLE off. We should probably provide
an empty function to handle this to avoid cluttering up pci-tegra.c
with conditionals.

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
[swarren, removed unnecessary return statement]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Tegra20 HW appears to have a bug such that PCIe device interrupts,
whether they are legacy IRQs or MSI, are lost when LP2 is enabled. To
work around this, simply disable LP2 if any PCIe devices with interrupts
are present. Detect this via the IRQ domain map operation. This is
slightly over-conservative; if a device with an interrupt is present but
the driver does not actually use them, LP2 will still be disabled.
However, this is a reasonable trade-off which enables a simpler
workaround.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>