arm64: psci: add support for PSCI invocations from the kernel

This patch adds support for the Power State Coordination Interface
defined by ARM, allowing Linux to request CPU-centric power-management
operations from firmware implementing the PSCI protocol.

Signed-off-by: Will Deacon <will.deacon@arm.com>
[Marc: s/u32/u64/ in the relevant spots, and switch from an initcall
 to an simpler init function]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 894c1e5..113db86 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -50,6 +50,7 @@
 #include <asm/tlbflush.h>
 #include <asm/traps.h>
 #include <asm/memblock.h>
+#include <asm/psci.h>
 
 unsigned int processor_id;
 EXPORT_SYMBOL(processor_id);
@@ -261,6 +262,8 @@
 
 	unflatten_device_tree();
 
+	psci_init();
+
 #ifdef CONFIG_SMP
 	smp_init_cpus();
 #endif