arm64: defconfig: Enable the PSCI CPUidle driver

Enable the PSCI CPUidle driver to replace the functionality
previously provided by the generic ARM CPUidle driver through
CPU operations.

Link: https://lore.kernel.org/r/20190814125239.6270-2-lorenzo.pieralisi@arm.comSigned-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/configs/defconfig

@@ -72,6 +72,7 @@ CONFIG_RANDOMIZE_BASE=y
 CONFIG_HIBERNATION=y
 CONFIG_WQ_POWER_EFFICIENT_DEFAULT=y
 CONFIG_ARM_CPUIDLE=y
+CONFIG_ARM_PSCI_CPUIDLE=y
 CONFIG_CPU_FREQ=y
 CONFIG_CPU_FREQ_STAT=y
 CONFIG_CPU_FREQ_GOV_POWERSAVE=m