ARM: tegra: fix compile-testing PCI host driver

The tegra_cpuidle_pcie_irqs_in_use() function is stubbed out for non-ARM
builds, but now we can compile-test the Tegra pci driver on non-Tegra
ARM platforms as well, which results in a new link error:

drivers/pci/host/pci-tegra.o: In function `tegra_pcie_map_irq':
pci-tegra.c:(.text+0x288): undefined reference to `tegra_cpuidle_pcie_irqs_in_use'
drivers/pci/host/pci-tegra.o: In function `tegra_msi_map':
pci-tegra.c:(.text+0xba0): undefined reference to `tegra_cpuidle_pcie_irqs_in_use'

This adapts the #ifdef statement to match the exact condition under which
the function can be called.

Fixes: 51bc085d ("PCI: Improve host drivers compile test coverage")
Cc: Rob Herring <robh@kernel.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>