driver/ddr: Fix DDR4 driver for ARM

Previously the driver was only tested on Power SoCs. Different barrier
instructions are needed for ARM SoCs.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/arch/arm/include/asm/arch-fsl-lsch3/config.h b/arch/arm/include/asm/arch-fsl-lsch3/config.h
index c1c718e..b17410a 100644
--- a/arch/arm/include/asm/arch-fsl-lsch3/config.h
+++ b/arch/arm/include/asm/arch-fsl-lsch3/config.h
@@ -43,7 +43,11 @@
 /* DDR */
 #define CONFIG_SYS_FSL_DDR_LE
 #define CONFIG_VERY_BIG_RAM
+#ifdef CONFIG_SYS_FSL_DDR4
+#define CONFIG_SYS_FSL_DDRC_GEN4
+#else
 #define CONFIG_SYS_FSL_DDRC_ARM_GEN3	/* Enable Freescale ARM DDR3 driver */
+#endif
 #define CONFIG_SYS_FSL_DDR		/* Freescale DDR driver */
 #define CONFIG_SYS_LS2_DDR_BLOCK1_SIZE	((phys_size_t)2 << 30)
 #define CONFIG_MAX_MEM_MAPPED		CONFIG_SYS_LS2_DDR_BLOCK1_SIZE
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 214f3ea..6d18eb3 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -136,6 +136,7 @@
  * TODO: The kernel offers some more advanced versions of barriers, it might
  * have some advantages to use them instead of the simple one here.
  */
+#define mb()		asm volatile("dsb sy" : : : "memory")
 #define dmb()		__asm__ __volatile__ ("" : : : "memory")
 #define __iormb()	dmb()
 #define __iowmb()	dmb()
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index d8b7b97..a5257e9 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -123,6 +123,9 @@
 #define iobarrier_r()  eieio()
 #define iobarrier_w()  eieio()
 
+#define mb()	sync()
+#define isb()	isync()
+
 /*
  * Non ordered and non-swapping "raw" accessors
  */