arm64: kernel: add __init marker to PSCI init functions

arm64: kernel: add __init marker to PSCI init functions

PSCI init functions must be marked as __init so that they are freed
by the kernel upon boot.

This patch marks the PSCI init functions as such since they need not
be persistent in the kernel address space after the kernel has booted.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b9e97ef93c630404f305350d88d09391d1a55648)
Signed-off-by: Mark Brown <broonie@kernel.org>