fix(st-ddr): add missing debug.h

In a later patch, the stm32mp1_def.h will be reworked. The inclusion
of common/debug.h may not be done there through another included file.
Add this header inclusion in the files that need it.

Change-Id: I83687f7910032ca38c0856796580a650e1e41a68
Signed-off-by: Yann Gautier <yann.gautier@st.com>

drivers/st/ddr/stm32mp_ddr.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <common/debug.h>
 #include <drivers/delay_timer.h>
 #include <drivers/st/stm32mp_ddr.h>
 #include <drivers/st/stm32mp_ddrctrl_regs.h>

drivers/st/ddr/stm32mp_ddr_test.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <common/debug.h>
 #include <drivers/st/stm32mp_ddr_test.h>
 #include <lib/mmio.h>
 

drivers/st/ddr/stm32mp_ram.c

@@ -7,6 +7,7 @@
 #include <errno.h>
 #include <stdbool.h>
 
+#include <common/debug.h>
 #include <common/fdt_wrappers.h>
 #include <drivers/st/stm32mp_ram.h>
 #include <libfdt.h>