ACPI: Remove the unused find_acpi_cpu_cache_topology()

The sole user of this find_acpi_cpu_cache_topology() was arm64 topology
which is now consolidated into the generic arch_topology without the need
of this function.

Drop the unused function find_acpi_cpu_cache_topology().

Reported-by: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>