arm: cpuinfo: drop L1 cache type print from pr_info to pr_debug

This message is printed every time a CPU in hotplugged in,
resulting in log noise and hurting hotplug latency. Silence
it by default, by dropping it to a pr_debug.

Change-Id: I05b643a90abc17e0134830874555e79138237261
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>