rockchip: tpl: allow to call board/SoC-specific code before DRAM init

This defines a weak tpl_board_init function that can be used for running
board/SoC-specific code before the DRAM init happens, similarly to
spl_board_init() for SPL.

Reviewed-by: Paul Kocialkowski <paulk@sys-base.io>
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/tpl.c b/arch/arm/mach-rockchip/tpl.c
index bbb9329..6b880f1 100644
--- a/arch/arm/mach-rockchip/tpl.c
+++ b/arch/arm/mach-rockchip/tpl.c
@@ -21,6 +21,10 @@
 #include <timestamp.h>
 #endif
 
+__weak void tpl_board_init(void)
+{
+}
+
 void board_init_f(ulong dummy)
 {
 	struct udevice *dev;
@@ -54,6 +58,8 @@
 	if (IS_ENABLED(CONFIG_SYS_ARCH_TIMER))
 		timer_init();
 
+	tpl_board_init();
+
 	ret = uclass_get_device(UCLASS_RAM, 0, &dev);
 	if (ret) {
 		printf("DRAM init failed: %d\n", ret);