cputlb: Merge tlb_table_flush_by_mmuidx into tlb_flush_one_mmuidx_locked

cputlb: Merge tlb_table_flush_by_mmuidx into tlb_flush_one_mmuidx_locked

There is only one caller for tlb_table_flush_by_mmuidx.  Place
the result at the earlier line number, due to an expected user
in the near future.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>