With the new Tegra186 PMC driver merged, anything that relies on the previous
PMC driver fails to link when that is disabled:
arch/arm/mach-tegra/pm.o: In function `tegra_pm_set':
pm.c:(.text.tegra_pm_set+0x3c): undefined reference to `tegra_pmc_enter_suspend_mode'
arch/arm/mach-tegra/pm.o: In function `tegra_suspend_enter':
pm.c:(.text.tegra_suspend_enter+0x4): undefined reference to `tegra_pmc_get_suspend_mode'
arch/arm/mach-tegra/pm.o: In function `tegra_init_suspend':
pm.c:(.init.text+0x1c): undefined reference to `tegra_pmc_get_suspend_mode'
pm.c:(.init.text+0x74): undefined reference to `tegra_pmc_set_suspend_mode'