powerpc/perf: Trace imc events detection and cpuhotplug

Patch detects trace-imc events, does memory initilizations for each online
cpu, and registers cpuhotplug call-backs.

Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/opal-imc.c

@@ -284,6 +284,9 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
 		case IMC_TYPE_THREAD:
 			domain = IMC_DOMAIN_THREAD;
 			break;
+		case IMC_TYPE_TRACE:
+			domain = IMC_DOMAIN_TRACE;
+			break;
 		default:
 			pr_warn("IMC Unknown Device type \n");
 			domain = -1;