dm: sandbox: i2c_rtc: Drop fdtdec.h header

This is not needed in this driver. Drop it.

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

drivers/rtc/i2c_rtc_emul.c

@@ -16,7 +16,6 @@
 
 #include <common.h>
 #include <dm.h>
-#include <fdtdec.h>
 #include <i2c.h>
 #include <os.h>
 #include <rtc.h>