idc: make two functions cold

Make idc_init_thread() and idc_init() cold, they are only invoked
during initialisation.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/idc/idc.c

@@ -15,6 +15,7 @@
 #include <rtos/alloc.h>
 #include <rtos/clk.h>
 #include <sof/lib/cpu.h>
+#include <sof/lib/memory.h>
 #include <sof/lib/notifier.h>
 #include <sof/lib/pm_runtime.h>
 #include <sof/lib/uuid.h>
@@ -419,10 +420,12 @@ void idc_cmd(struct idc_msg *msg)
 }
 
 /* Runs on each CPU */
-int idc_init(void)
+__cold int idc_init(void)
 {
 	struct idc **idc = idc_get();
 
+	assert_can_be_cold();
+
 	tr_dbg(&idc_tr, "entry");
 
 	/* initialize idc data */

src/idc/zephyr_idc.c

@@ -196,11 +196,13 @@ int idc_send_msg(struct idc_msg *msg, uint32_t mode)
 	return ret;
 }
 
-void idc_init_thread(void)
+__cold void idc_init_thread(void)
 {
 	char thread_name[] = "idc_p4wq0";
 	int cpu = cpu_get_id();
 
+	assert_can_be_cold();
+
 	k_p4wq_enable_static_thread(q_zephyr_idc + cpu,
 				    _p4threads_q_zephyr_idc + cpu, BIT(cpu));