risc-v: add pm initialization functions.

Signed-off-by: zhongan <zhongan@xiaomi.com>

arch/risc-v/src/common/up_initialize.c

@@ -124,6 +124,16 @@ void up_initialize(void)
   idle->adj_stack_ptr   = (FAR void *)g_idle_topstack;
   idle->adj_stack_size  = CONFIG_IDLETHREAD_STACKSIZE;
 
+#ifdef CONFIG_PM
+  /* Initialize the power management subsystem.  This MCU-specific function
+   * must be called *very* early in the initialization sequence *before* any
+   * other device drivers are initialized (since they may attempt to register
+   * with the power management subsystem).
+   */
+
+  up_pminitialize();
+#endif
+
   /* Register devices */
 
 #if defined(CONFIG_DEV_NULL)

arch/risc-v/src/common/up_internal.h

@@ -201,6 +201,14 @@ void up_restorefpu(const uint32_t *regs);
 #  define up_restorefpu(regs)
 #endif
 
+/* Power management *********************************************************/
+
+#ifdef CONFIG_PM
+void up_pminitialize(void);
+#else
+#  define up_pminitialize()
+#endif
+
 /* Low level serial output **************************************************/
 
 void up_lowputc(char ch);