[nrf fromtree] arch: riscv: Add support for CPU load measuring

Add sys_trace_idle_exit to RISCV cpu_idle functions and allow
enabling CPU_LOAD module for RISCV and disable it for SMP.

Signed-off-by: Krzysztof Chruściński <[email protected]>
(cherry picked from commit 4026daa)

Author: nordic-krch

arch/riscv/core/cpu_idle.c

@@ -12,6 +12,7 @@ void arch_cpu_idle(void)
 {
 	sys_trace_idle();
 	__asm__ volatile("wfi");
+	sys_trace_idle_exit();
 	irq_unlock(MSTATUS_IEN);
 }
 #endif
@@ -21,6 +22,7 @@ void arch_cpu_atomic_idle(unsigned int key)
 {
 	sys_trace_idle();
 	__asm__ volatile("wfi");
+	sys_trace_idle_exit();
 	irq_unlock(key);
 }
 #endif

subsys/debug/Kconfig

@@ -434,8 +434,8 @@ config CS_TRACE_DEFMT
 
 config CPU_LOAD
 	select TRACING
-	# Currently hooks are added only to Cortex M architecture.
-	depends on CPU_CORTEX_M
+	depends on CPU_CORTEX_M || RISCV
+	depends on !SMP
 	bool "CPU load measurement"
 
 # Workaround for not being able to have commas in macro arguments