rockchip: use 'arch-rockchip' as header file path

Rockchip use 'arch-rockchip' instead of arch-$(SOC) as common
header file path, so that we can get the correct path directly.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/drivers/serial/serial_rockchip.c b/drivers/serial/serial_rockchip.c
index 35fefd7..b1718f7 100644
--- a/drivers/serial/serial_rockchip.c
+++ b/drivers/serial/serial_rockchip.c
@@ -9,7 +9,7 @@
 #include <dt-structs.h>
 #include <ns16550.h>
 #include <serial.h>
-#include <asm/arch/clock.h>
+#include <asm/arch-rockchip/clock.h>
 
 #if defined(CONFIG_ROCKCHIP_RK3188)
 struct rockchip_uart_platdata {