usb: dwc3-of-simple: Drop redundant inclding header file

The fdtdec.h is no use in this file, remove the include code.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/usb/host/dwc3-of-simple.c b/drivers/usb/host/dwc3-of-simple.c
index 45df614..e4abc6f 100644
--- a/drivers/usb/host/dwc3-of-simple.c
+++ b/drivers/usb/host/dwc3-of-simple.c
@@ -12,7 +12,6 @@
 
 #include <common.h>
 #include <dm.h>
-#include <fdtdec.h>
 #include <reset.h>
 #include <clk.h>