armv8: fsl-layerscape: Make DDR non secure in MMU tables

DDR has been set as secure in MMU tables. Non-secure master such
as SDHC DMA cannot access data correctly. Mixing secure and non-
secure MMU entries requirs the MMU tables themselves in secure
memory. This patch moves MMU tables into a secure DDR area.

Early MMU tables are changed to set DDR as non-secure. A new
table is added into final MMU tables so secure memory can have
2MB granuality.

gd->secure_ram tracks the location of this secure memory. For
ARMv8 SoCs, the RAM base is not zero and RAM is divided into several
banks. gd->secure_ram needs to be maintained before using. This
maintenance is board-specific, depending on the SoC and memory
bank of the secure memory falls into.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/ls1043aqds/ddr.c b/board/freescale/ls1043aqds/ddr.c
index 705e384..42d9068 100644
--- a/board/freescale/ls1043aqds/ddr.c
+++ b/board/freescale/ls1043aqds/ddr.c
@@ -126,6 +126,15 @@
 
 void dram_init_banksize(void)
 {
+	/*
+	 * gd->secure_ram tracks the location of secure memory.
+	 * It was set as if the memory starts from 0.
+	 * The address needs to add the offset of its bank.
+	 */
 	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
 	gd->bd->bi_dram[0].size = gd->ram_size;
+#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
+	gd->secure_ram = gd->bd->bi_dram[0].start + gd->secure_ram;
+	gd->secure_ram |= MEM_RESERVE_SECURE_MAINTAINED;
+#endif
 }