imx:mx6ul add dram spl configuration and header file

1. Define two structures mx6ul_iomux_ddr_regs and mx6ul_iomux_grp_regs.
2. Add a new function mx6ul_dram_iocfg to configure dram io.
3. Refactor MMDC1 macro, discard "#ifdef CONFIG_MX6SX". Since
   only mmdc0 channel exists on i.MX6SX/UL, redefine MMDC1 macro support
   runtime check, but not hardcoding #ifdef macros.
4. Introduce mx6ul-ddr.h, which includes the register address for DRAM
   IO configuration.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
diff --git a/arch/arm/include/asm/arch-mx6/mx6ul-ddr.h b/arch/arm/include/asm/arch-mx6/mx6ul-ddr.h
new file mode 100644
index 0000000..ed11c4b
--- /dev/null
+++ b/arch/arm/include/asm/arch-mx6/mx6ul-ddr.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_ARCH_MX6UL_DDR_H__
+#define __ASM_ARCH_MX6UL_DDR_H__
+
+#ifndef CONFIG_MX6UL
+#error "wrong CPU"
+#endif
+
+#define MX6_IOM_DRAM_DQM0	0x020e0244
+#define MX6_IOM_DRAM_DQM1	0x020e0248
+
+#define MX6_IOM_DRAM_RAS	0x020e024c
+#define MX6_IOM_DRAM_CAS	0x020e0250
+#define MX6_IOM_DRAM_CS0	0x020e0254
+#define MX6_IOM_DRAM_CS1	0x020e0258
+#define MX6_IOM_DRAM_SDWE_B	0x020e025c
+#define MX6_IOM_DRAM_SDODT0	0x020e0260
+#define MX6_IOM_DRAM_SDODT1	0x020e0264
+#define MX6_IOM_DRAM_SDBA0	0x020e0268
+#define MX6_IOM_DRAM_SDBA1	0x020e026c
+#define MX6_IOM_DRAM_SDBA2	0x020e0270
+#define MX6_IOM_DRAM_SDCKE0	0x020e0274
+#define MX6_IOM_DRAM_SDCKE1	0x020e0278
+#define MX6_IOM_DRAM_SDCLK_0	0x020e027c
+#define MX6_IOM_DRAM_SDQS0	0x020e0280
+#define MX6_IOM_DRAM_SDQS1	0x020e0284
+#define MX6_IOM_DRAM_RESET	0x020e0288
+
+#define MX6_IOM_GRP_ADDDS	0x020e0490
+#define MX6_IOM_DDRMODE_CTL	0x020e0494
+#define MX6_IOM_GRP_B0DS	0x020e0498
+#define MX6_IOM_GRP_DDRPK	0x020e049c
+#define MX6_IOM_GRP_CTLDS	0x020e04a0
+#define MX6_IOM_GRP_B1DS	0x020e04a4
+#define MX6_IOM_GRP_DDRHYS	0x020e04a8
+#define MX6_IOM_GRP_DDRPKE	0x020e04ac
+#define MX6_IOM_GRP_DDRMODE	0x020e04b0
+#define MX6_IOM_GRP_DDR_TYPE	0x020e04b4
+
+#endif	/*__ASM_ARCH_MX6SX_DDR_H__ */