arm64: kaslr: fix breakage with CONFIG_MODVERSIONS=y

As it turns out, the KASLR code breaks CONFIG_MODVERSIONS, since the
kcrctab has an absolute address field that is relocated at runtime
when the kernel offset is randomized.

This has been fixed already for PowerPC in the past, so simply wire up
the existing code dealing with this issue.

Cc: <stable@vger.kernel.org>
Fixes: f80fb3a3

 ("arm64: add support for kernel ASLR")
Tested-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>