rockchip: adding the missing "/" in entries of boot_devices

Without the prefix, "same-as-spl" in `u-boot,spl-boot-order` will not work
as expected. When board_boot_order() `spl-boot-order.c` meets
"same-as-spl", it gets the conf by looking the boot_devices table by boot
source, and parse the node by the conf with:

   node = fdt_path_offset(blob, conf);

which will failed without the "/" indicating the path.

Currently only entries of boot_devices in rk3399 have the "/" prefix.
Therefore add the missing ones in other boards.

Signed-off-by: Levin Du <djw@t-chip.com.cn>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/rk3188/rk3188.c b/arch/arm/mach-rockchip/rk3188/rk3188.c
index 95f0e3c..1b012f7 100644
--- a/arch/arm/mach-rockchip/rk3188/rk3188.c
+++ b/arch/arm/mach-rockchip/rk3188/rk3188.c
@@ -14,8 +14,8 @@
 #define GRF_BASE	0x20008000
 
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
-	[BROM_BOOTSOURCE_EMMC] = "dwmmc@1021c000",
-	[BROM_BOOTSOURCE_SD] = "dwmmc@10214000",
+	[BROM_BOOTSOURCE_EMMC] = "/dwmmc@1021c000",
+	[BROM_BOOTSOURCE_SD] = "/dwmmc@10214000",
 };
 
 #ifdef CONFIG_DEBUG_UART_BOARD_INIT
diff --git a/arch/arm/mach-rockchip/rk322x/rk322x.c b/arch/arm/mach-rockchip/rk322x/rk322x.c
index cd0bf8a..562117e 100644
--- a/arch/arm/mach-rockchip/rk322x/rk322x.c
+++ b/arch/arm/mach-rockchip/rk322x/rk322x.c
@@ -8,8 +8,8 @@
 #include <asm/arch-rockchip/hardware.h>
 
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
-	[BROM_BOOTSOURCE_EMMC] = "dwmmc@30020000",
-	[BROM_BOOTSOURCE_SD] = "dwmmc@30000000",
+	[BROM_BOOTSOURCE_EMMC] = "/dwmmc@30020000",
+	[BROM_BOOTSOURCE_SD] = "/dwmmc@30000000",
 };
 
 #ifdef CONFIG_DEBUG_UART_BOARD_INIT
diff --git a/arch/arm/mach-rockchip/rk3288/rk3288.c b/arch/arm/mach-rockchip/rk3288/rk3288.c
index 057ce92..987b4e0 100644
--- a/arch/arm/mach-rockchip/rk3288/rk3288.c
+++ b/arch/arm/mach-rockchip/rk3288/rk3288.c
@@ -22,8 +22,8 @@
 #define GRF_BASE	0xff770000
 
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
-	[BROM_BOOTSOURCE_EMMC] = "dwmmc@ff0f0000",
-	[BROM_BOOTSOURCE_SD] = "dwmmc@ff0c0000",
+	[BROM_BOOTSOURCE_EMMC] = "/dwmmc@ff0f0000",
+	[BROM_BOOTSOURCE_SD] = "/dwmmc@ff0c0000",
 };
 
 #ifdef CONFIG_SPL_BUILD
diff --git a/arch/arm/mach-rockchip/rk3328/rk3328.c b/arch/arm/mach-rockchip/rk3328/rk3328.c
index c2448d7..8c81242e 100644
--- a/arch/arm/mach-rockchip/rk3328/rk3328.c
+++ b/arch/arm/mach-rockchip/rk3328/rk3328.c
@@ -19,8 +19,8 @@
 #define FW_DDR_CON_REG		0xFF7C0040
 
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
-	[BROM_BOOTSOURCE_EMMC] = "rksdmmc@ff520000",
-	[BROM_BOOTSOURCE_SD] = "rksdmmc@ff500000",
+	[BROM_BOOTSOURCE_EMMC] = "/rksdmmc@ff520000",
+	[BROM_BOOTSOURCE_SD] = "/rksdmmc@ff500000",
 };
 
 static struct mm_region rk3328_mem_map[] = {
diff --git a/arch/arm/mach-rockchip/rk3368/rk3368.c b/arch/arm/mach-rockchip/rk3368/rk3368.c
index 7ccd417..20ae797 100644
--- a/arch/arm/mach-rockchip/rk3368/rk3368.c
+++ b/arch/arm/mach-rockchip/rk3368/rk3368.c
@@ -54,8 +54,8 @@
 struct mm_region *mem_map = rk3368_mem_map;
 
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
-	[BROM_BOOTSOURCE_EMMC] = "dwmmc@ff0f0000",
-	[BROM_BOOTSOURCE_SD] = "dwmmc@ff0c0000",
+	[BROM_BOOTSOURCE_EMMC] = "/dwmmc@ff0f0000",
+	[BROM_BOOTSOURCE_SD] = "/dwmmc@ff0c0000",
 };
 
 #ifdef CONFIG_ARCH_EARLY_INIT_R