rockchip: rk3188: add boot_devices mapping to support 'same-as-spl'

The driver need a mapping to get the dts node by boot srouce ID.
Signed-off-by: NKever Yang <kever.yang@rock-chips.com>

arch/arm/mach-rockchip/rk3188/rk3188.c

@@ -4,11 +4,17 @@
  */
 #include <common.h>
 #include <asm/io.h>
+#include <asm/arch-rockchip/bootrom.h>
 #include <asm/arch-rockchip/grf_rk3188.h>
 #include <asm/arch-rockchip/hardware.h>
 
 #define GRF_BASE	0x20008000
 
+const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
+	[BROM_BOOTSOURCE_EMMC] = "dwmmc@1021c000",
+	[BROM_BOOTSOURCE_SD] = "dwmmc@10214000",
+};
+
 #ifdef CONFIG_DEBUG_UART_BOARD_INIT
 void board_debug_uart_init(void)
 {