event: Convert arch_cpu_init_dm() to use events

Instead of a special function, send an event after driver model is inited
and adjust the boards which use this function.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/riscv/include/asm/system.h

@@ -7,6 +7,8 @@
 #ifndef __ASM_RISCV_SYSTEM_H
 #define __ASM_RISCV_SYSTEM_H
 
+struct event;
+
 /*
  * Interrupt configuring macros.
  *
@@ -14,4 +16,7 @@
  *
  */
 
+/* Hook to set up the CPU (called from SPL too) */
+int riscv_cpu_setup(void *ctx, struct event *event);
+
 #endif	/* __ASM_RISCV_SYSTEM_H */