arch_topology: Localize cap_parsing_failed to topology_parse_cpu_capacity()

cap_parsing_failed is only required in topology_parse_cpu_capacity() to
know if we have already tried to allocate raw_capacity and failed, or if
at least one of the cpu_node didn't had the required
"capacity-dmips-mhz" property.

All other users can use raw_capacity instead of cap_parsing_failed.

Make sure we set raw_capacity to NULL after we free it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Tested-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>