target-arm: Restrict AArch64 TLB flushes to the MMU indexes they must touch

Now we have the ability to flush the TLB only for specific MMU indexes,
update the AArch64 TLB maintenance instruction implementations to only
flush the parts of the TLB they need to, rather than doing full flushes.

We take the opportunity to remove some duplicate functions (the per-asid
tlb ops work like the non-per-asid ones because we don't support
flushing a TLB only by ASID) and to bring the function names in line
with the architectural TLBI operation names.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1439548879-1972-4-git-send-email-peter.maydell@linaro.org