arm: Replace __this_cpu_ptr with raw_cpu_ptr

__this_cpu_ptr is being phased out. So replace with raw_cpu_ptr.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>