rockchip: intruduce common BROM_BOOTSOURCE_ID_ADDR

The boot source from BootRom is store at a fix offset of IRAM,
update to use the common macro instead of rk3399 specific one.
Signed-off-by: NKever Yang <kever.yang@rock-chips.com>

arch/arm/include/asm/arch-rockchip/bootrom.h

@@ -55,6 +55,6 @@ enum {
 /**
  * Locations of the boot-device identifier in SRAM
  */
-#define RK3399_BROM_BOOTSOURCE_ID_ADDR   0xff8c0010
+#define BROM_BOOTSOURCE_ID_ADDR   (CONFIG_IRAM_BASE + 0x10)
 
 #endif

arch/arm/mach-rockchip/rk3399-board-spl.c

@@ -35,7 +35,7 @@ static const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
 
 const char *board_spl_was_booted_from(void)
 {
-	u32  bootdevice_brom_id = readl(RK3399_BROM_BOOTSOURCE_ID_ADDR);
+	u32  bootdevice_brom_id = readl(BROM_BOOTSOURCE_ID_ADDR);
 	const char *bootdevice_ofpath = NULL;
 
 	if (bootdevice_brom_id < ARRAY_SIZE(boot_devices))