rockchip: Move stdint header to the offending header file

The stdint header was introduced to rk3399's plat_sip_calls.c in order
to fix missing stdint definitions. However, ordering headers
alphabetically caused the fix to be ineffective, as stint was then
included after the offending header file (dfs.h).

Move the stdint include to that header to properly fix the issue.

Change-Id: Ieaad37a7932786971488ab58fc5b169bfa79e197
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>

plat/rockchip/rk3399/drivers/dram/dfs.h

@@ -7,6 +7,8 @@
 #ifndef __SOC_ROCKCHIP_RK3399_DFS_H__
 #define __SOC_ROCKCHIP_RK3399_DFS_H__
 
+#include <stdint.h>
+
 struct rk3399_sdram_default_config {
 	unsigned char bl;
 	/* 1:auto precharge, 0:never auto precharge */

plat/rockchip/rk3399/plat_sip_calls.c

@@ -11,7 +11,6 @@
 #include <plat_sip_calls.h>
 #include <rockchip_sip_svc.h>
 #include <runtime_svc.h>
-#include <stdint.h>
 
 #define RK_SIP_DDR_CFG		0x82000008
 #define DRAM_INIT		0x00