perf/x86/uncore: Correct the number of CHAs on SPR

The number of CHAs from the discovery table on some SPR variants is
incorrect, because of a firmware issue. An accurate number can be read
from the MSR UNC_CBO_CONFIG.

Fixes: 949b1138

 ("perf/x86/intel/uncore: Add Sapphire Rapids server CHA support")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230508140206.283708-1-kan.liang@linux.intel.com