arm: socfpga: Move Stratix10 and Agilex SPL common code

Move Stratix10 and Agilex SPL common code to spl_soc64.c.
We are in preparation for new n5x device support.
No functional change in this patch.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
Reviewed-by: Ley Foon Tan <ley.foon.tan@intel.com>
diff --git a/arch/arm/mach-socfpga/spl_soc64.c b/arch/arm/mach-socfpga/spl_soc64.c
new file mode 100644
index 0000000..cb98ab3
--- /dev/null
+++ b/arch/arm/mach-socfpga/spl_soc64.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2020 Intel Corporation. All rights reserved
+ *
+ */
+
+#include <common.h>
+#include <spl.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+u32 spl_boot_device(void)
+{
+	return BOOT_DEVICE_MMC1;
+}
+
+#if IS_ENABLED(CONFIG_SPL_MMC_SUPPORT)
+u32 spl_boot_mode(const u32 boot_device)
+{
+	if (IS_ENABLED(CONFIG_SPL_FS_FAT) || IS_ENABLED(CONFIG_SPL_FS_EXT4))
+		return MMCSD_MODE_FS;
+	else
+		return MMCSD_MODE_RAW;
+}
+#endif