event: Convert misc_init_f() to use events

This hook can be implmented using events, for the three boards that
actually use it.

Add the event type and event handlers. Drop CONFIG_MISC_INIT_F since we
can just use CONFIG_EVENT to control this. Since sandbox always enables
CONFIG_EVENT, we can drop the defconfig lines there too.

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

include/init.h

@@ -217,7 +217,6 @@ int init_cache_f_r(void);
 int print_cpuinfo(void);
 #endif
 int timer_init(void);
-int misc_init_f(void);
 
 #if defined(CONFIG_DTB_RESELECT)
 int embedded_dtb_select(void);