kernel: Minor optimization of event & semaphore include files

Since it is now possible to send both events and semaphores from
a fiber or ISR without having to use a command packet set, there
is no longer any need to reference the command packet include file.

Change-Id: Ibf2d96bc8ef0fd2a3db6f896c7a1201ab9b85bf7
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>

include/microkernel/event.h

@@ -33,7 +33,7 @@ extern "C" {
  * @{
  */
 
-#include <microkernel/command_packet.h>
+#include <microkernel/base_api.h>
 
 /* well-known events */
 extern const kevent_t TICK_EVENT;

include/microkernel/semaphore.h

@@ -34,7 +34,7 @@
 extern "C" {
 #endif
 
-#include <microkernel/command_packet.h>
+#include <microkernel/base_api.h>
 
 /**
  *