perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization

There were some issues about the uncore driver tried to access
non-existing boxes, which caused boot crashes. These issues have
been all fixed. But we should avoid boot failures if that ever
happens again.

This patch intends to prevent this kind of potential issues.
It moves uncore_box_init out of driver initialization. The box
will be initialized when it's first enabled.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421729665-5912-1-git-send-email-kan.liang@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>