[zephyr] Fix CHIPDevicePlatformEvent.h include dependency

Currently the CHIPDevicePlatformEvent depends on the
SystemPacketBuffer which is included
in the CHIPDeviceEvent.h too late.

The problem is silently worked around in the application
when the <platform/PlatformManager.h> include is preceded
by other headers that pull in SystemPacketBuffer.h, but we need
a proper fix.

Signed-off-by: Marcin Kajor <marcin.kajor@nordicsemi.no>

Author: kkasperczyk-no

src/platform/Zephyr/CHIPDevicePlatformEvent.h

@@ -23,7 +23,7 @@
 
 #pragma once
 
-#include <platform/CHIPDeviceEvent.h>
+#include <system/SystemPacketBuffer.h>
 
 #include <zephyr/bluetooth/bluetooth.h>