arm64: Use __tlbi() macros in KVM code

Refactor the KVM code to use the __tlbi macros, which will allow an errata
workaround that repeats tlbi dsb sequences to only change one location.
This is not intended to change the generated assembly and comparing before
and after vmlinux objdump shows no functional changes.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>