imx8qm_mek: Include fdt_support.h header

Include fdt_support.h header file to fix the following sparse warning:

board/freescale/imx8qm_mek/imx8qm_mek.c:116:5: warning: no previous
prototype for ‘ft_board_setup’ [-Wmissing-prototypes]

Signed-off-by: Alifer Moraes <alifer.wsdm@gmail.com>

board/freescale/imx8qm_mek/imx8qm_mek.c

@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <init.h>
 #include <linux/libfdt.h>
+#include <fdt_support.h>
 #include <asm/io.h>
 #include <asm/gpio.h>
 #include <asm/arch/clock.h>