powerpc/fsl_booke/kaslr: Provide correct r5 value for relocated kernel

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8OHAZ



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Value stored in r5 is an indication on whether the system is booted from
PROM Of-type client-interface. It's value must be preserved and provided
when booting relocated kernel.

Signed-off-by: GUO Zihua <guozihua@huawei.com>