spl: add g_dnl_get_board_bcd_device_number

Add g_dnl_get_board_bcd_device_number, the new BCD value is used by uuu to distinguish
if the SPL supports the SDPV.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index 76a5f7a..aa2686b 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -187,6 +187,12 @@
 
 	return 0;
 }
+
+#define SDPV_BCD_DEVICE 0x500
+int g_dnl_get_board_bcd_device_number(int gcnum)
+{
+	return SDPV_BCD_DEVICE;
+}
 #endif
 
 #if defined(CONFIG_SPL_MMC_SUPPORT)